Hybrid electric vehicle and power system thereof

ABSTRACT

This application discloses a hybrid power automobile and a power system thereof. The power system includes: an engine, where the engine outputs power to wheels of the hybrid power automobile through a clutch; a power motor, where the power motor is configured to output a drive force to the wheels of the hybrid power automobile; a power battery, where the power battery is configured to supply power to the power motor; a DC-DC converter; and an auxiliary motor connected to the engine, where the auxiliary motor is connected to the power motor, the DC-DC converter, and the power battery, and when performing power generation under driving of the engine, the auxiliary motor implements at least one of charging the power battery, supplying power to the power motor, and supplying power to the DC-DC converter. Therefore, low-speed electric balance and low-speed smoothness of the entire vehicle can be maintained.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. 371 U.S. national stage applicationentry of PCT/CN2018/081049, filed on Mar. 29, 2018, which claimspriority to Chinese Patent Application No. 201710211041.9, filed withthe Chinese Patent Office on Mar. 31, 2017 and entitled “HYBRID POWERAUTOMOBILE AND POWER SYSTEM THEREOF”, and Chinese Patent Application No.201720340394.4, filed with the Chinese Patent Office on Mar. 31, 2017and entitled “HYBRID POWER AUTOMOBILE AND POWER SYSTEM THEREOF”, whichare incorporated herein by reference in their entireties.

FIELD

The present invention relates to the field of vehicle technologies, andin particular, to a power system of a hybrid power automobile and ahybrid power automobile having the system.

BACKGROUND

With continuous consumption of energy sources, development and use ofnew energy vehicle models have gradually become a trend. A hybrid powerautomobile as one of new energy source vehicle models is driven throughan engine and/or a motor.

However, in the prior art, while serving as a drive motor, a front motorof the hybrid power automobile further serves as a generator.Consequently, during low-speed travelling, a rotational speed of thefront motor is relatively low, power generation power and powergeneration efficiency are also quite low. As a result, power consumptionrequirements of the low-speed travelling cannot be satisfied.Consequently, it is relatively difficult for the entire vehicle tomaintain electric balance at a low speed.

SUMMARY

An objective of the present invention is to at least resolve one of thetechnical problems in the related art to some extent. To this end, afirst objective of the present invention is to propose a power system ofa hybrid power automobile, to implement low-speed electric balance ofthe entire vehicle.

A second objective of the present invention is to propose a hybrid powerautomobile.

To achieve the foregoing objectives, an embodiment of a first aspect ofthe present invention proposes a power system of a hybrid powerautomobile, including: an engine, where the engine outputs power towheels of the hybrid power automobile through a clutch; a power motor,where the power motor is configured to output a drive force to thewheels of the hybrid power automobile; a power battery, where the powerbattery is configured to supply power to the power motor; a DC-DCconverter; and an auxiliary motor connected to the engine, where theauxiliary motor is connected to the power motor, the DC-DC converter,and the power battery, and when performing power generation underdriving of the engine, the auxiliary motor implements at least one ofcharging the power battery, supplying power to the power motor, andsupplying power to the DC-DC converter.

According to the power system of a hybrid power automobile proposed inthis embodiment of the present invention, the engine outputs power tothe wheels of the hybrid power automobile through the clutch, the powermotor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, andwhen performing power generation under driving of the engine, theauxiliary motor implements at least one of charging the power battery,supplying power to the power motor, and supplying power to the DC-DCconverter, thereby maintaining low-speed electric balance and low-speedsmoothness of the entire vehicle, and improving performance of theentire vehicle.

To achieve the foregoing objectives, an embodiment of a second aspect ofthe present invention proposes a hybrid power automobile, including thepower system of a hybrid power automobile.

According to the hybrid power automobile proposed in this embodiment ofthe present invention, low-speed electric balance and low-speedsmoothness of the entire vehicle can be maintained, and performance ofthe entire vehicle can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a power system of a hybrid powerautomobile according to an embodiment of the present invention;

FIG. 2a is a schematic structural diagram of a power system of a hybridpower automobile according to an embodiment of the present invention;

FIG. 2b is a schematic structural diagram of a power system of a hybridpower automobile according to another embodiment of the presentinvention;

FIG. 3 is a schematic block diagram of a power system of a hybrid powerautomobile according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a transmission structure between anengine and corresponding wheels according to an embodiment of thepresent invention;

FIG. 5 is a schematic diagram of a transmission structure between anengine and corresponding wheels according to another embodiment of thepresent invention;

FIG. 6 is a schematic block diagram of a power system of a hybrid powerautomobile according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of an engine universal characteristiccurve according to an embodiment of the present invention;

FIG. 8 is a structural block diagram of a power system of a hybrid powerautomobile according to an embodiment of the present invention;

FIG. 9a is a schematic structural diagram of a power system of a hybridpower automobile according to an embodiment of the present invention;

FIG. 9b is a schematic structural diagram of a power system of a hybridpower automobile according to another embodiment of the presentinvention;

FIG. 9c is a schematic structural diagram of a power system of a hybridpower automobile according to still another embodiment of the presentinvention;

FIG. 10 is a structural block diagram of a voltage stabilization circuitaccording to an embodiment of the present invention;

FIG. 11 is a principle diagram of voltage stabilization controlaccording to an embodiment of the present invention;

FIG. 12 is a structural block diagram of a power system of a hybridpower automobile according to a specific embodiment of the presentinvention;

FIG. 13 is a schematic block diagram of a hybrid power automobileaccording to an embodiment of the present invention;

FIG. 14 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention;

FIG. 15 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to a specific embodimentof the present invention;

FIG. 16 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to another embodiment ofthe present invention;

FIG. 17 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to another specificembodiment of the present invention;

FIG. 18 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to still anotherembodiment of the present invention;

FIG. 19 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to still another specificembodiment of the present invention;

FIG. 20 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to yet another embodimentof the present invention;

FIG. 21 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to yet another specificembodiment of the present invention;

FIG. 22 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to yet another embodimentof the present invention; and

FIG. 23 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to yet another specificembodiment of the present invention.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the presentinvention. The embodiments described herein with reference to drawingsare explanatory, illustrative, and should be used to generallyunderstand the present invention. The following embodiments describedwith reference to the accompanying drawings are exemplary, and areintended to describe the present invention and cannot be construed as alimitation to the present invention.

A power system of a hybrid power automobile proposed in an embodiment ofan aspect of the present invention is described below with reference toFIG. 1 to FIG. 5, and the power system provides sufficient power andelectric energy for normal travelling of the hybrid power automobile.

FIG. 1 is a schematic block diagram of a power system of a hybrid powerautomobile according to an embodiment of the present invention. As shownin FIG. 1, the power system of a hybrid power automobile includes: anengine 1, a power motor 2, a power battery 3, a DC-DC converter 4, andan auxiliary motor 5.

As shown in FIG. 1 to FIG. 3, the engine 1 outputs power to wheels 7 ofthe hybrid power automobile through a clutch 6; and the power motor 2 isconfigured to output a drive force to the wheels 7 of the hybrid powerautomobile. To be specific, the power system of this embodiment of thepresent invention may provide power for normal travelling of the hybridpower automobile through the engine 1 and/or the power motor 2. In someembodiments of the present invention, a power source of the power systemmay be the engine 1 and the power motor 2. To be specific, either of theengine 1 and the power motor 2 may individually output power to thewheels 7, or the engine 1 and the power motor 2 may simultaneouslyoutput power to the wheels 7.

The power battery 3 is configured to supply power to the power motor 2.The auxiliary motor 5 is connected to the engine 1. For example, theauxiliary motor 5 may be connected to the engine 1 through a wheel trainside of the engine 1. The auxiliary motor 5 is connected to the powermotor 2, the DC-DC converter 4, and the power battery 3, and whenperforming power generation under driving of the engine 1, the auxiliarymotor 5 implements at least one of charging the power battery 3,supplying power to the power motor 2, and supplying power to the DC-DCconverter 4. In other words, the engine 1 may drive the auxiliary motor5 to perform power generation, and electric energy generated by theauxiliary motor 5 may be provided to at least one of the power battery3, the power motor 2, and the DC-DC converter 4. It should be understoodthat, the engine 1 may drive, while outputting power to the wheels 7,the auxiliary motor 5 to perform power generation, or may individuallydrive the auxiliary motor 5 to perform power generation.

Therefore, the power motor 2 and the auxiliary motor 5 respectivelyserve as a drive motor and a generator in a one-to-one correspondence,and because the auxiliary motor 5 has relatively high power generationpower and power generation efficiency at a low speed, power consumptionrequirements of low-speed travelling may be satisfied, and low-speedelectric balance of the entire vehicle and low-speed smoothness of theentire vehicle may be maintained, to improve power performance of theentire vehicle.

In some embodiments, the auxiliary motor 5 may be a belt-driven startergenerator (BSG) motor. It should be noted that, the auxiliary motor 5belongs to a high-voltage motor. For example, a power generation voltageof the auxiliary motor 5 is equivalent to a voltage of the power battery3, and therefore electric energy generated by the auxiliary motor 5 maydirectly charge the power battery 3 without voltage conversion, and mayfurther directly supply power to the power motor 2 and/or the DC-DCconverter 4. Moreover, the auxiliary motor 5 also belongs to anefficient generator. For example, power generation efficiency above 97%may be achieved provided that the auxiliary motor 5 is driven at anidling rotational speed of the engine 1 to perform power generation.

Additionally, in some embodiments of the present invention, theauxiliary motor 5 may be configured to start the engine 1, that is, theauxiliary motor 5 may have a function of starting the engine 1. Forexample, when starting the engine 1, the auxiliary motor 5 may drive acrank shaft of the engine 1 to rotate, so that a piston of the engine 1reaches an ignition location, thereby starting the engine 1. Therefore,the auxiliary motor 5 may implement a function of a starter in a relatedtechnology.

As described above, both the engine 1 and the power motor 2 may beconfigured to drive the wheels 7 of the hybrid power automobile. Forexample, as shown in FIG. 2a , the engine 1 and the power motor 2jointly drive same wheels of the hybrid power automobile, for example, apair of front wheels 71 (including a left front wheel and a right frontwheel). For another example, as shown in FIG. 2b , the engine 1 maydrive first wheels of the hybrid power automobile, for example, a pairof front wheels 71 (including a left front wheel and a right frontwheel), and the power motor 2 may drive second wheels of the hybridpower automobile, for example, a pair of rear wheels 72 (including aleft rear wheel and a right rear wheel).

In other words, when the engine 1 and the power motor 2 jointly drivethe pair of front wheels 71, a drive force of the power system is outputto the pair of front wheels 71, and the entire vehicle may use a drivemanner of two-wheel drive; or when the engine 1 drives the pair of frontwheels 71 and the power motor 2 drives the pair of rear wheels 72, adrive force of the power system is output to the pair of front wheels 71and the pair of rear wheels 72, and the entire vehicle may use a drivemanner of four-wheel drive.

Further, when the engine 1 and the power motor 2 jointly drive samewheels, as shown in FIG. 2a , the power system of a hybrid powerautomobile further includes a differential 8, a main reducer 9, and atransmission 90, where the engine 1 outputs power to the first wheels ofthe hybrid power automobile, for example, the pair of front wheels 71through the clutch 6, the transmission 90, the main reducer 9, and thedifferential 8, and the power motor 2 outputs a drive force to the firstwheels of the hybrid power automobile, for example, the pair of frontwheels 71 through the main reducer 9 and the differential 8. The clutch6 and the transmission 90 may be integrated.

When the engine 1 drives the first wheels and the power motor 2 drivesthe second wheels, as shown in FIG. 2b , the power system of a hybridpower automobile further includes a first transmission 91 and a secondtransmission 92, where the engine 1 outputs power to the first wheels ofthe hybrid power automobile, for example, the pair of front wheels 71through the clutch 6 and the first transmission 91, and the power motor2 outputs a drive force to the second wheels of the hybrid powerautomobile, for example, the pair of rear wheels 72 through the secondtransmission 92. The clutch 6 and the first transmission 91 may beintegrated.

Further, in some embodiments of the present invention, as shown in FIG.1 to FIG. 3, the auxiliary motor 5 further includes a first controller51, the power motor 2 further includes a second controller 21, and theauxiliary motor 5 is connected to the power battery 3 and the DC-DCconverter 4 through the first controller 51 and connected to the powermotor 2 through the first controller 51 and the second controller 21.

Specifically, the first controller 51 is connected to the secondcontroller 21, the power battery 3, and the DC-DC converter 4, the firstcontroller 51 may have an AC-DC conversion unit, the auxiliary motor 5may generate an alternating current during power generation, and theAC-DC conversion unit may convert the alternating current generated bythe auxiliary motor 5 during power generation into a high-voltage directcurrent, for example, a 600V high-voltage direct current, so as toimplement at least one of charging the power battery 3, supplying powerto the power motor 2, and supplying power to the DC-DC converter 4.

The second controller 21 may have a DC-AC conversion unit, the firstcontroller 51 may convert the alternating current generated by theauxiliary motor 5 during power generation into a high-voltage directcurrent, and the DC-AC conversion unit may then convert the high-voltagedirect current into which the first controller 51 converts thealternating current into an alternating current, so as to supply powerto the power motor 2.

In other words, as shown in FIG. 3, when the auxiliary motor 5 performspower generation, the auxiliary motor 5 may charge the power battery 3and/or supply power to the DC-DC converter 4 through the firstcontroller 51. To be specific, the auxiliary motor 5 may implement anyone or two of charging the power battery 3 and supplying power to theDC-DC converter 4 through the first controller 51. Moreover, theauxiliary motor 5 may further supply power to the power motor 2 throughthe first controller 51 and the second controller 21.

Further, as shown in FIG. 1 to FIG. 3, the DC-DC converter 4 is furtherconnected to the power battery 3. The DC-DC converter 4 is furtherconnected to the power motor 2 through the second controller 21.

In some embodiments, as shown in FIG. 3, the first controller 51 has afirst direct current end DC1, the second controller 21 has a seconddirect current end DC2, the DC-DC converter 4 has a third direct currentend DC3, and the third direct current end DC3 of the DC-DC converter 4may be connected to the first direct current end DC1 of the firstcontroller 51, so as to perform DC-DC conversion on a high-voltagedirect current output by the first controller 51 through the firstdirect current end DC1. Moreover, the third direct current end DC3 ofthe DC-DC converter 4 may be further connected to the power battery 3,and then the first direct current end DC1 of the first controller 51 maybe connected to the power battery 3, so that the first controller 51outputs a high-voltage direct current to the power battery 3 through thefirst direct current end DC1 to charge the power battery 3. Further, thethird direct current end DC3 of the DC-DC converter 4 may be furtherconnected to the second direct current end DC2 of the second controller21, and then the first direct current end DC1 of the first controller 51may be connected to the second direct current end DC2 of the secondcontroller 21, so that the first controller 51 outputs a high-voltagedirect current to the second controller 21 through the first directcurrent end DC1 to supply power to the power motor 2.

Further, as shown in FIG. 3, the DC-DC converter 4 is further connectedto a first electric appliance device 10 and a low-voltage storagebattery 20 in the hybrid power automobile to supply power to the firstelectric appliance device 10 and the low-voltage storage battery 20, andthe low-voltage storage battery 20 is further connected to the firstelectric appliance device 10.

In some embodiments, as shown in FIG. 3, the DC-DC converter 4 furtherhas a fourth direct current end DC4, and the DC-DC converter 4 mayconvert a high-voltage direct current output by the power battery 3and/or a high-voltage direct current output by the auxiliary motor 5through the first controller 51 into a low-voltage direct current, andoutput the low-voltage direct current through the fourth direct currentend DC4. To be specific, the DC-DC converter 4 may convert any one ortwo of the high-voltage direct current output by the power battery 3 andthe high-voltage direct current output by the auxiliary motor 5 throughthe first controller 51 into a low-voltage direct current, and outputthe low-voltage direct current through the fourth direct current endDC4. Further, the fourth direct current end DC4 of the DC-DC converter 4may be connected to the first electric appliance device 10, so as tosupply power to the first electric appliance device 10, where the firstelectric appliance device 10 may be a low-voltage power consumptiondevice, and includes but is not limited to a lamp and a radio. Thefourth direct current end DC4 of the DC-DC converter 4 may be furtherconnected to the low-voltage storage battery 20, so as to charge thelow-voltage storage battery 20.

Moreover, the low-voltage storage battery 20 is connected to the firstelectric appliance device 10, so as to supply power to the firstelectric appliance device 10. Particularly, when the auxiliary motor 5stops power generation and the power battery 3 is faulty or has aninsufficient power level, the low-voltage storage battery 20 may supplypower to the first electric appliance device 10, thereby ensuringlow-voltage power consumption of the entire vehicle, ensuring that theentire vehicle may implement travelling in a pure fuel mode, andimproving travelling mileage of the entire vehicle.

As described above, the third direct current end DC3 of the DC-DCconverter 4 is connected to the first controller 51, the fourth directcurrent end DC4 of the DC-DC converter 4 is connected to the firstelectric appliance device 10 and the low-voltage storage battery 20, andwhen the power motor 2, the second controller 21, and the power battery3 are faulty, the auxiliary motor 5 may perform power generation tosupply power to the first electric appliance device 10 and/or charge thelow-voltage storage battery 20 through the first controller 51 and theDC-DC converter 4, so that the hybrid power automobile travels in thepure fuel mode. To be specific, when the power motor 2, the secondcontroller 21, and the power battery 3 are faulty, the auxiliary motor 5may perform power generation to implement any one or two of supplyingpower to the first electric appliance device 10 and charging thelow-voltage storage battery 20 through the first controller 51 and theDC-DC converter 4, so that the hybrid power automobile travels in thepure fuel mode.

In other words, when the power motor 2, the second controller 21, andthe power battery 3 are faulty, the first controller 51 may convert thealternating current generated by the auxiliary motor 5 during powergeneration into a high-voltage direct current, and the DC-DC converter 4may convert the high-voltage direct current into which the firstcontroller 51 converts the alternating current into a low-voltage directcurrent, so as to supply power to the first electric appliance device 10and/or charge the low-voltage storage battery 20, that is, implement anyone or two of supplying power to the first electric appliance device 10and charging the low-voltage storage battery 20.

Therefore, the auxiliary motor 5 and the DC-DC converter 4 have oneindividual power supply channel, and when the power motor 2, the secondcontroller 21, and the power battery 3 are faulty, electrically operateddrive cannot be implemented. In this case, through the individual powersupply channel of the auxiliary motor 5 and the DC-DC converter 4,low-voltage power consumption of the entire vehicle may be ensured, toensure that the entire vehicle may implement travelling in the pure fuelmode, and improve travelling mileage of the entire vehicle.

Further, with reference to the embodiment in FIG. 3, the firstcontroller 51, the second controller 21, and the power battery 3 arefurther respectively connected to a second electric appliance device 30in the hybrid power automobile.

In some embodiments, as shown in FIG. 3, the first direct current endDC1 of the first controller 51 may be connected to the second electricappliance device 30, and when the auxiliary motor 5 performs powergeneration, the auxiliary motor 5 may directly supply power to thesecond electric appliance device 30 through the first controller 51. Inother words, the AC-DC conversion unit of the first controller 51 mayfurther convert the alternating current generated by the auxiliary motor5 during power generation into a high-voltage direct current, anddirectly supply power to the second electric appliance device 30.

The power battery 3 may be further connected to the second electricappliance device 30, so as to supply power to the second electricappliance device 30. To be specific, the high-voltage direct currentoutput by the power battery 3 may be directly supplied to the secondelectric appliance device 30.

The second electric appliance device 30 may be a high-voltage electricappliance device, and may include but is not limited to an airconditioner compressor and a positive temperature coefficient (PTC)heater.

As described above, power generation through the auxiliary motor 5 maybe implemented to charge the power battery 3, supply power the powermotor 2, or supply power to the first electric appliance device 10 andthe second electric appliance device 30. Moreover, the power battery 3may supply power to the power motor 2 or supply power to the secondelectric appliance device 30 through the second controller 21, or maysupply power to the first electric appliance device 10 and/or thelow-voltage storage battery 20 through the DC-DC converter 4. Therefore,power supply manners of the entire vehicle are enriched, powerconsumption requirements of the entire vehicle under different workingconditions are satisfied, and performance of the entire vehicle isimproved.

It should be noted that, in this embodiment of the present invention, alow voltage may be a voltage of 12 V or 24 V, and a high voltage may bea voltage of 600 V, but this embodiment is not limited thereto.

Therefore, in the power system of a hybrid power automobile of thisembodiment of the present invention, the engine is enabled not toparticipate in drive at a low speed, and therefore the clutch is notused, thereby reducing abrasion or slip friction of the clutch, reducingan unsmooth feeling, and improving comfortableness; and at a low speed,the engine is enabled to operate in an economical area, to perform onlypower generation but does not perform drive, thereby reducing fuelconsumption, reducing noise of the engine, maintaining low-speedelectric balance and low-speed smoothness of the entire vehicle, andimproving performance of the entire vehicle. Moreover, the auxiliarymotor can directly charge the power battery, may also supply power to alow-voltage device, for example, the low-voltage storage battery or thefirst electric appliance device, and may further serve as a starter.

A specific embodiment of a power system of a hybrid power automobile isdescribed in detail below with reference to FIG. 4, and the embodimentis applicable to a power system in which an engine 1 and a power motor 2jointly drive same wheels, that is, a two-wheel drive hybrid powerautomobile. It should be noted that, the embodiment mainly describes aspecific transmission structure between the engine 1, the power motor 2,and wheels 7, particularly a structure of the transmission 90 in FIG. 2a, and remaining parts are basically the same as those of the embodimentin FIG. 1 and FIG. 3. Details are not described herein again.

It should be further noted that, a plurality of input shafts, aplurality of output shafts, a motor power shaft 931, related gears onthe shafts, gear change elements, and the like in the followingembodiments may be used to form the transmission 90 in FIG. 2 a.

In some embodiments, as shown in FIG. 1, FIG. 3, and FIG. 4, a powersystem of a hybrid power automobile mainly includes an engine 1, a powermotor 2, a power battery 3, a DC-DC converter 4, an auxiliary motor 5, aplurality of input shafts (for example, a first input shaft 911 and asecond input shaft 912), a plurality of output shafts (for example, afirst output shaft 921 and a second output shaft 922), and a motor powershaft 931, related gears on the shafts, and gear change elements (forexample, a synchronizer).

As shown in FIG. 4, the engine 1 outputs power to wheels 7 of the hybridpower automobile through a clutch 6, for example, a double clutch 2 d inan example in FIG. 4. When power is transferred between the engine 1 andthe input shafts, the engine 1 is set to be selectively bonded to atleast one of the plurality of input shafts through the double clutch 2d. In other words, when the engine 1 transmits power to the inputshafts, the engine 1 can be selectively bonded to one of the pluralityof input shafts to transmit power, or the engine 1 can be selectivelybonded to two or more of the plurality of input shafts simultaneously totransmit power.

For example, in the example in FIG. 4, the plurality of input shafts mayinclude two input shafts, namely, the first input shaft 911 and thesecond input shaft 912, the second input shaft 912 may be coaxiallysleeved on the first input shaft 911, and the engine 1 can beselectively bonded to one of the first input shaft 911 and the secondinput shaft 912 through the double clutch 2 d to transmit power.Alternatively, in particular, the engine 1 can be further bonded to thefirst input shaft 911 and the second input shaft 912 simultaneously totransmit power. Certainly, it should be understood that, the engine 1may be further disconnected from the first input shaft 911 and thesecond input shaft 912 simultaneously.

The plurality of output shafts may include two output shafts, namely,the first output shaft 921 and the second output shaft 922, and thefirst output shaft 921 and the second output shaft 922 are respectivelydisposed parallel to the first input shaft 911.

Transmission may be performed between an input shaft and an output shaftthrough a shift gear pair. For example, a driving shift gear is disposedon each input shaft. To be specific, a driving shift gear is disposed oneach of the first input shaft 911 and the second input shaft 912. Adriven shift gear is disposed on each output shaft. To be specific, adriven shift gear is disposed on each of the first output shaft 921 andthe second output shaft 922. Driven shift gears are correspondinglymeshed with driving shift gears, thereby forming a plurality of gearpairs whose speed ratios are different.

In some embodiments of the present invention, six-gear transmission maybe used between the input shaft and the output shaft, that is, there area first-gear gear pair, a second-gear gear pair, a third-gear gear pair,a fourth-gear gear pair, a fifth-gear gear pair, and a sixth-gear gearpair. However, the present invention is not limited thereto. A person ofordinary skill in the art may adaptively increase or reduce a quantityof shift gear pairs according to transmission needs, and the presentinvention is not limited to the six-gear transmission shown in thisembodiment of the present invention.

As shown in FIG. 4, the motor power shaft 931 is set to be capable ofbeing linked to one of the plurality of output shafts (for example, thefirst output shaft 921 and the second output shaft 922), and throughlinkage between the motor power shaft 931 and the one of the outputshafts, power may be transferred between the motor power shaft 931 andthe one of the output shafts. For example, power passing through theoutput shaft (for example, power output from the engine 1) may be outputto the motor power shaft 931, or power passing through the motor powershaft 931 (for example, power output from the power motor 2) may beoutput to the output shaft.

It should be noted that, the “link” may be understood as that multipleparts (for example, two parts) move in a linkage manner. Using anexample in which two parts are linked, when one part moves, the otherpart moves together.

For example, in some embodiments of the present invention, that a gearis linked to a shaft may be understood as that when the gear rotates,the linked shaft also rotates, or when the shaft rotates, the linkedgear also rotates.

For another example, that a shaft is linked to a shaft may be understoodas that when one shaft rotates, the other linked shaft also rotates.

For still another example, that a gear is linked to a gear may beunderstood as that when one gear rotates, the other linked gear alsorotates.

Unless otherwise specified, the descriptions about “linkage” below inthe present invention should be understood in this way.

The power motor 2 is set to be capable of being linked to the motorpower shaft 931. For example, the power motor 2 may output generatedpower to the motor power shaft 931, thereby outputting a drive force tothe wheels 7 of the hybrid power automobile through the motor powershaft 931.

It should be noted that, in the description of the present invention,the motor power shaft 931 may be a motor shaft of the power motor 2.Certainly, it may be understood that, the motor power shaft 931 and themotor shaft of the power motor 2 may alternatively be two individualshafts.

In some embodiments, as shown in FIG. 4, an output portion 221 maydifferentially rotate relative to the one (for example, the secondoutput shaft 922) of the output shafts. In other words, the outputportion 221 and the output shaft can independently rotate at differentrotational speeds.

Further, the output portion 221 is set to be selectively bonded to theone of the output shafts to rotate in synchronization with the outputshaft. In other words, the output portion 221 can differentially rotateor synchronously rotate relative to the output shaft. In short, relativeto the one of the output shafts, the output portion 221 may be bonded tosynchronously rotate, and certainly may alternatively be disconnected todifferentially rotate.

As shown in FIG. 4, the output portion 221 may be freely sleeved on theone of the output shafts, but is not limited thereto. For example, inthe example in FIG. 4, the output portion 221 is freely sleeved on thesecond output shaft 922, that is, the output portion 221 and the secondoutput shaft 922 can differentially rotate at different rotationalspeeds.

As described above, the output portion 221 may rotate in synchronizationwith the one of the output shafts. For example, a correspondingsynchronizer may be added as required to implement a function ofsynchronization between the output portion 221 and the output shaft. Thesynchronizer may be an output portion synchronizer 221 c, and the outputportion synchronizer 221 c is set to synchronize the output portion 221and the one of the output shafts.

In some embodiments, the power motor 2 is configured to output a driveforce to the wheels 7 of the hybrid power automobile, and the engine 1and the power motor 2 jointly drive same wheels of the hybrid powerautomobile. With reference to the example in FIG. 4, a differential 75of the vehicle may be arranged between a pair of front wheels 71 orbetween a pair of rear wheels 72. In some examples of the presentinvention, when the power motor 2 drives the pair of front wheels 71,the differential 75 may be located between the pair of front wheels 71.

A function of the differential 75 is to enable left and right drivewheels to roll at different angular speeds when the vehicle is corneringor is travelling on an uneven road surface, so as to ensure that the twodrive wheels perform pure roll motion on a ground surface. A mainreducer driven gear 74 of the main reducer 9 is disposed on thedifferential 75. For example, the main reducer driven gear 74 may bearranged on a casing of the differential 75. The main reducer drivengear 74 may be a bevel gear, but is not limited thereto.

In some embodiments, as shown in FIG. 1, the power battery 3 isconfigured to supply power to the power motor 2. The auxiliary motor 5is connected to the engine 1, the auxiliary motor 5 is further connectedto the power motor 2, the DC-DC converter 4, and the power battery 3,and when performing power generation under driving of the engine 1, theauxiliary motor 5 implements at least one of charging the power battery3, supplying power to the power motor 2, and supplying power to theDC-DC converter 4.

Another specific embodiment of a power system of a hybrid powerautomobile is described in detail below with reference to FIG. 5, andthe embodiment is similarly applicable to a power system in which anengine 1 and a power motor 2 jointly drive same wheels, that is, atwo-wheel drive hybrid power automobile. It should be noted that, theembodiment mainly describes a specific transmission structure betweenthe engine 1, the power motor 2, and wheels 7, particularly a structureof the transmission 90 in FIG. 2a , and remaining parts are basicallythe same as those of the embodiment in FIG. 1 and FIG. 3. Details arenot described herein again.

It should be further noted that, a plurality of input shafts, aplurality of output shafts, a motor power shaft 931, related gears onthe shafts, gear change elements, and the like in the followingembodiments may be used to form the transmission 90 in FIG. 2 a.

In some embodiments, as shown in FIG. 1, FIG. 3, and FIG. 5, a powersystem of a hybrid power automobile mainly includes an engine 1, a powermotor 2, a power battery 3, a DC-DC converter 4, an auxiliary motor 5, aplurality of input shafts (for example, a first input shaft 911 and asecond input shaft 912), a plurality of output shafts (for example, afirst output shaft 921 and a second output shaft 922), and a motor powershaft 931, related gears on the shafts, and gear change elements (forexample, a synchronizer).

As shown in FIG. 5, the engine 1 outputs power to wheels 7 of the hybridpower automobile through a clutch 6, for example, a double clutch 2 d inan example in FIG. 4. When power is transferred between the engine 1 andthe input shafts, the engine 1 is set to be selectively bonded to atleast one of the plurality of input shafts through the double clutch 2d. In other words, when the engine 1 transmits power to the inputshafts, the engine 1 can be selectively bonded to one of the pluralityof input shafts to transmit power, or the engine 1 can be selectivelybonded to two or more of the plurality of input shafts simultaneously totransmit power.

For example, in the example in FIG. 5, the plurality of input shafts mayinclude two input shafts, namely, the first input shaft 911 and thesecond input shaft 912, the second input shaft 912 is coaxially sleevedon the first input shaft 911, and the engine 1 can be selectively bondedto one of the first input shaft 911 and the second input shaft 912through the double clutch 2 d to transmit power. Alternatively, inparticular, the engine 1 can be further bonded to the first input shaft911 and the second input shaft 912 simultaneously to transmit power.Certainly, it should be understood that, the engine 1 may be furtherdisconnected from the first input shaft 911 and the second input shaft912 simultaneously.

The plurality of output shafts may include two output shafts, namely,the first output shaft 921 and the second output shaft 922, and thefirst output shaft 921 and the second output shaft 922 are disposedparallel to the first input shaft 911.

Transmission may be performed between an input shaft and an output shaftthrough a shift gear pair. For example, a driving shift gear is disposedon each input shaft. To be specific, a driving shift gear is disposed oneach of the first input shaft 911 and the second input shaft 912. Adriven shift gear is disposed on each output shaft. To be specific, adriven shift gear is disposed on each of the first output shaft 921 andthe second output shaft 922. Driven shift gears are correspondinglymeshed with driving shift gears, thereby forming a plurality of gearpairs whose speed ratios are different.

In some embodiments of the present invention, six-gear transmission maybe used between the input shaft and the output shaft, that is, there area first-gear gear pair, a second-gear gear pair, a third-gear gear pair,a fourth-gear gear pair, a fifth-gear gear pair, and a sixth-gear gearpair. However, the present invention is not limited thereto. A person ofordinary skill in the art may adaptively increase or reduce a quantityof shift gear pairs according to transmission needs, and the presentinvention is not limited to the six-gear transmission shown in thisembodiment of the present invention.

As shown in FIG. 5, at least one reverse-gear output gear 81 is freelysleeved on one of the output shafts (for example, the first output shaft921 and the second output shaft 922), and reverse-gear synchronizers(for example, a fifth-gear synchronizer 5 c and a sixth-gearsynchronizer 6 c) used to bond the reverse-gear output gear 81 arefurther disposed on the output shaft. In other words, a reverse-gearsynchronizer synchronizes the corresponding reverse-gear output gear 81and the output shaft, so that the output shaft and the reverse-gearoutput gear 81 that is synchronized by the reverse-gear synchronizer cansynchronously rotate, and then reverse-gear power can be output from theoutput shaft.

In some embodiments, as shown in FIG. 5, there is one reverse-gearoutput gear 81, and the one reverse-gear output gear 81 may be freelysleeved on the second output shaft 922. However, the present inventionis not limited thereto. In some other embodiments, there mayalternatively be two reverse-gear output gears 81, and the tworeverse-gear output gears 81 are simultaneously freely sleeved on thesecond output shaft 922. Certainly, it may be understood that, there mayalternatively be three or more reverse-gear output gears 81.

A reverse-gear shaft 89 is set to be linked to one of the input shafts(for example, the first input shaft 911 and the second input shaft 912)and is further linked to the at least one reverse-gear output gear 81.For example, power passing through the one of the input shafts may betransferred to the reverse-gear output gear 81 through the reverse-gearshaft 89, and therefore reverse-gear power can be output from thereverse-gear output gear 81. In an example of the present invention,each reverse-gear output gear 81 is freely sleeved on the second outputshaft 922, and the reverse-gear shaft 89 is linked to the first inputshaft 911. For example, reverse-gear power output by the engine 1 maypass through the first input shaft 911 and the reverse-gear shaft 89 andthen be output to the reverse-gear output gear 81.

The motor power shaft 931 is described in detail below. A first motorpower shaft gear 31 and a second motor power shaft gear 32 are freelysleeved on the motor power shaft 931. The first motor power shaft gear31 may be in meshed transmission with the main reducer driven gear 74,so as to transmit a drive force to the wheels 7 of the hybrid powerautomobile.

The second motor power shaft gear 32 is set to be linked to one of thedriven shift gears. When the hybrid power automobile having the powersystem according to this embodiment of the present invention is undersome working conditions, power output by the power source may betransferred between the second motor power shaft gear 32 and the drivenshift gear linked to the second motor power shaft gear 32. In this case,the second motor power shaft gear 32 and the driven shift gear arelinked. For example, the second motor power shaft gear 32 and asecond-gear driven gear 2 b are linked, and the second motor power shaftgear 32 and the second-gear driven gear 2 b may be directly meshed or bein indirect transmission through an intermediate transmission component.

Further, a motor power shaft synchronizer 33 c is further disposed onthe motor power shaft 931, the motor power shaft synchronizer 33 c islocated between the first motor power shaft gear 31 and the second motorpower shaft gear 32, and the motor power shaft synchronizer 33 c mayselectively bond the first motor power shaft gear 31 or the second motorpower shaft gear 32 and the motor power shaft 931. For example, in theexample in FIG. 5, a bonding sleeve of the motor power shaftsynchronizer 33 c may be bonded to the second motor power shaft gear 32if the bonding sleeve moves to the left, and may be bonded to the firstmotor power shaft gear 31 if the bonding sleeve moves to the right.

The power motor 2 is set to be capable of being linked to the motorpower shaft 931. For example, the power motor 2 may output generatedpower to the motor power shaft 931, thereby outputting a drive force tothe wheels 7 of the hybrid power automobile through the motor powershaft 931.

The first motor power shaft gear 31 is meshed with the main reducerdriven gear 74, and therefore the power motor 2 may be bonded to thefirst motor power shaft gear 31 through the motor power shaftsynchronizer 33 c to output the generated power directly from the firstmotor power shaft gear 31, thereby shortening a transmission chain,reducing intermediate transmission components, and improvingtransmission efficiency.

Second, a transmission manner of the motor power shaft 931 and of thepower motor 2 is described in detail with reference to a specificembodiment.

In some embodiments, as shown in FIG. 5, a third motor power shaft gear33 is further fixedly disposed on the motor power shaft 931, and thepower motor 2 is set to be in direct meshed transmission or indirecttransmission with the third motor power shaft gear 33.

Further, a first motor gear 511 is disposed on a motor shaft of thepower motor 2, and the first motor gear 511 is in transmission with thethird motor power shaft gear 33 through an intermediate gear 512. Foranother example, the power motor 2 may alternatively be coaxiallyconnected to the motor power shaft 931.

In some embodiments, the power motor 2 is configured to output a driveforce to the wheels 7 of the hybrid power automobile, and the engine 1and the power motor 2 jointly drive same wheels of the hybrid powerautomobile. With reference to the example in FIG. 5, a differential 75of the vehicle may be arranged between a pair of front wheels 71 orbetween a pair of rear wheels 72. In some examples of the presentinvention, when the power motor 2 drives the pair of front wheels 71,the differential 75 may be located between the pair of front wheels 71.

A function of the differential 75 is to enable left and right drivewheels to roll at different angular speeds when the vehicle is corneringor is travelling on an uneven road surface, so as to ensure that the twodrive wheels perform pure roll motion on a ground surface. A mainreducer driven gear 74 of the main reducer 9 is disposed on thedifferential 75. For example, the main reducer driven gear 74 may bearranged on a casing of the differential 75. The main reducer drivengear 74 may be a bevel gear, but is not limited thereto.

Further, a first output shaft output gear 211 is fixedly disposed on thefirst output shaft 921, the first output shaft output gear 211 rotatesin synchronization with the first output shaft 921, and the first outputshaft output gear 211 is in meshed transmission with the main reducerdriven gear 74, so that power passing through the first output shaft 921can be transferred to the main reducer driven gear 74 and thedifferential 75 from the first output shaft output gear 211.

Similarly, a second output shaft output gear 212 is fixedly disposed onthe second output shaft 922, the second output shaft output gear 212rotates in synchronization with the second output shaft 922, and thesecond output shaft output gear 212 is in meshed transmission with themain reducer driven gear 74, so that power passing through the secondoutput shaft 922 can be transferred to the main reducer driven gear 74and the differential 75 from the second output shaft output gear 212.

Similarly, the first motor power shaft gear 31 may be configured tooutput the power passing through the motor power shaft 931, andtherefore the first motor power shaft gear 31 is similarly in meshedtransmission with the main reducer driven gear 74.

In some embodiments, as shown in FIG. 1, the power battery 3 isconfigured to supply power to the power motor 2. The auxiliary motor 5is connected to the engine 1, the auxiliary motor 5 is further connectedto the power motor 2, the DC-DC converter 4, and the power battery 3,and when performing power generation under driving of the engine 1, theauxiliary motor 5 implements at least one of charging the power battery3, supplying power to the power motor 2, and supplying power to theDC-DC converter 4.

Further, as shown in FIG. 6, the power system of a hybrid powerautomobile further includes a control module 101, and the control module101 is configured to control the power system of the hybrid powerautomobile. It should be understood that, the control module 101 may beintegration of controllers having a control function in the hybrid powerautomobile, for example, may be integration of a vehicle controller ofthe hybrid power automobile, the first controller 51 and the secondcontroller 21 in the embodiment in FIG. 3, and the like, but is notlimited thereto. A control method performed by the control module 101 isdescribed in detail below.

Embodiment 1

In some embodiments of the present invention, the control module 101 isconfigured to obtain an SOC (state of charge, also referred to asremaining power level) value of the power battery 3, an SOC value of thelow-voltage storage battery 20, and a maximum allowed power generationpower of the auxiliary motor 5, and determine, according to the SOCvalue of the power battery 3, the SOC value of the low-voltage storagebattery 20, and the maximum allowed power generation power of theauxiliary motor 5, whether the auxiliary motor 5 charges the powerbattery 3 and/or the low-voltage storage battery 20.

It should be noted that, the SOC value of the power battery 3 and theSOC value of the low-voltage storage battery 20 may be collected througha battery management system of the hybrid power automobile, andtherefore the battery management system sends the SOC value of the powerbattery 3 and the SOC value of the low-voltage storage battery 20 thatare collected to the control module 101, so that the control module 101obtains the SOC value of the power battery 3 and the SOC value of thelow-voltage storage battery 20.

Therefore, by charging the power battery, power consumption requirementsof the power motor and the high-voltage electric appliance device may beensured, and further it is ensured that the power motor drives theentire vehicle to normally travel; and by charging the low-voltagestorage battery, power consumption requirements of the low-voltageelectric appliance device may be ensured, and when the auxiliary motorstops power generation and the power battery is faulty or has aninsufficient power level, low-voltage power supply of the entire vehiclemay be implemented through the low-voltage storage battery, and furtherit is ensured that the entire vehicle may travel in the pure fuel mode,thereby improving travelling mileage of the entire vehicle.

According to a specific example of the present invention, the maximumallowed power generation power of the auxiliary motor 5 is related toperformance parameters and the like of the auxiliary motor 5 and theengine 1. In other words, the maximum allowed power generation power ofthe auxiliary motor 5 may be preset according to the performanceparameters and the like of the auxiliary motor 5 and the engine 1.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is less than a first preset SOC value and the SOC valueof the low-voltage storage battery 20 is greater than or equal to asecond preset SOC value, control the engine 1 to drive the auxiliarymotor 5 to perform power generation to charge the power battery 3.

It should be understood that, the first preset SOC value may be acharging limit value of the power battery 3, the second preset SOC valuemay be a charging limit value of the low-voltage storage battery 20, andthe first preset SOC value and the second preset SOC value may beindependently set according to performance of the batteries, and may bea same value or different values.

Specifically, after obtaining the SOC value of the power battery 3 andthe SOC value of the low-voltage storage battery 20, the control module101 may determine whether the SOC value of the power battery 3 is lessthan the first preset SOC value, and determine whether the SOC value ofthe low-voltage storage battery 20 is less than the second preset SOCvalue. If the SOC value of the power battery 3 is less than the firstpreset SOC value and the SOC value of the low-voltage storage battery 20is greater than or equal to the second preset SOC value, it indicatesthat the power battery 3 has a relatively low remaining power level andneeds to be charged, and the low-voltage storage battery 20 has arelatively high remaining power level and does not need to be charged.In this case, the control module 101 controls the engine 1 to drive theauxiliary motor 5 to perform power generation to charge the powerbattery 3.

As described above, the auxiliary motor 5 belongs to a high-voltagemotor. For example, a power generation voltage of the auxiliary motor 5is equivalent to a voltage of the power battery 3, and thereforeelectric energy generated by the auxiliary motor 5 may directly chargethe power battery 3 without voltage conversion.

The control module 101 is further configured to: when the SOC value ofthe power battery 3 is greater than or equal to the first preset SOCvalue and the SOC value of the low-voltage storage battery 20 is lessthan the second preset SOC value, control the engine 1 to drive theauxiliary motor 5 to perform power generation to charge the low-voltagestorage battery 20 through the DC-DC converter 4.

To be specific, if the SOC value of the power battery 3 is greater thanor equal to the first preset SOC value and the SOC value of thelow-voltage storage battery 20 is less than the second preset SOC value,it indicates the power battery 3 has a relatively high remaining powerlevel and does not need to be charged, and the low-voltage storagebattery 20 has a relatively low remaining power level and needs to becharged. In this case, the control module 101 controls the engine 1 todrive the auxiliary motor 5 to perform power generation to charge thelow-voltage storage battery 20 through the DC-DC converter 4.

As described above, the auxiliary motor 5 belongs to a high-voltagemotor. For example, a power generation voltage of the auxiliary motor 5is equivalent to a voltage of the power battery 3, and thereforeelectric energy generated by the auxiliary motor 5 needs to be subjectedto voltage conversion through the DC-DC converter 4 and then charge thelow-voltage storage battery 20.

Furthermore, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is less than the first preset SOC value and the SOCvalue of the low-voltage storage battery 20 is less than the secondpreset SOC value, obtain a charging power of the power battery 3according to the SOC value of the power battery 3, and obtain a chargingpower of the low-voltage storage battery 20 according to the SOC valueof the low-voltage storage battery 20; and when a sum of the chargingpower of the power battery 3 and the charging power of the low-voltagestorage battery 20 is greater than the maximum allowed power generationpower of the auxiliary motor 5, control the engine 1 to drive theauxiliary motor 5 to perform power generation to charge the low-voltagestorage battery 20 through the DC-DC converter 4.

Moreover, the control module 101 is further configured to: when the sumof the charging power of the power battery 3 and the charging power ofthe low-voltage storage battery 20 is less than or equal to the maximumallowed power generation power of the auxiliary motor 5, control theengine 1 to drive the auxiliary motor 5 to perform power generation tocharge the power battery 3, and to simultaneously charge the low-voltagestorage battery 20 through the DC-DC converter 4.

To be specific, if the SOC value of the power battery 3 is less than thefirst preset SOC value and the SOC value of the low-voltage storagebattery 20 is less than the second preset SOC value, it indicates thatthe power battery 3 and the low-voltage storage battery 20 each have arelatively low remaining power level, and need to be charged. In thiscase, the control module 101 calculates the charging power of the powerbattery 3 according to the SOC value of the power battery 3, calculatesthe charging power of the low-voltage storage battery 20 according tothe SOC value of the low-voltage storage battery 20, and furtherdetermines whether the sum of the charging power of the power battery 3and the charging power of the low-voltage storage battery 20 is greaterthan the maximum allowed power generation power of the auxiliary motor5.

If the sum of the charging power of the power battery 3 and the chargingpower of the low-voltage storage battery 20 is greater than the maximumallowed power generation power of the auxiliary motor 5, it indicatesthat the electric energy that can be generated by the auxiliary motor 5is insufficient to simultaneously charge the two batteries. In thiscase, the low-voltage storage battery 20 is preferentially charged, thatis, the engine 1 is controlled to drive the auxiliary motor 5 to performpower generation to charge the low-voltage storage battery 20 throughthe DC-DC converter 4.

If the sum of the charging power of the power battery 3 and the chargingpower of the low-voltage storage battery 20 is less than or equal to themaximum allowed power generation power of the auxiliary motor 5, itindicates that the electric energy that can be generated by theauxiliary motor 5 can simultaneously charge the two batteries. In thiscase, the power battery 3 and the low-voltage storage battery 20 aresimultaneously charged, that is, the engine 1 is controlled to drive theauxiliary motor 5 to perform power generation to charge the powerbattery 3, and simultaneously charge the low-voltage storage battery 20through the DC-DC converter 4.

Therefore, by preferentially charging the low-voltage storage battery,power consumption requirements of the low-voltage electric appliancedevice may be preferentially ensured, and further it may be ensured thatthe entire vehicle travels in the pure fuel mode when the power batteryhas an insufficient power level, thereby improving travelling mileage ofthe entire vehicle.

Certainly, it should be understood that, when the SOC value of the powerbattery 3 is greater than or equal to the first preset SOC value and theSOC value of the low-voltage storage battery 20 is greater than or equalto the second preset SOC value, it indicates that the power battery 3and the low-voltage storage battery 20 each have a relatively highremaining power level, and do not need to be charged. In this case, thepower battery 3 and the low-voltage storage battery 20 may be notcharged.

To sum up, according to the power system of a hybrid power automobileproposed in this embodiment of the present invention, the engine outputspower to the wheels of the hybrid power automobile through the clutch,the power motor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, andwhen performing power generation under driving of the engine, theauxiliary motor implements at least one of charging the power battery,supplying power to the power motor, and supplying power to the DC-DCconverter, and the control module determines, according to the SOC valueof the power battery, the SOC value of the low-voltage storage batteryand the maximum allowed power generation power of the auxiliary motor,whether the auxiliary motor charges the power battery and/or thelow-voltage storage battery. Therefore, the engine is enabled not toparticipate in drive at a low speed, and therefore the clutch is notused, thereby reducing abrasion or slip friction of the clutch, reducingan unsmooth feeling, and improving comfortableness; and at a low speed,the engine is enabled to operate in an economical area, to perform onlypower generation but does not perform drive, thereby reducing fuelconsumption, reducing noise of the engine, maintaining low-speedelectric balance and low-speed smoothness of the entire vehicle, andimproving performance of the entire vehicle. Moreover, the system notonly may charge the power battery, but also may charge the low-voltagestorage battery. Therefore, power consumption requirements of the powermotor and the high-voltage electric appliance device may be ensured, andfurther it is ensured that the power motor drives the entire vehicle tonormally travel; and power consumption requirements of the low-voltageelectric appliance device may be ensured, and further when the auxiliarymotor stops power generation and the power battery is faulty or has aninsufficient power level, it may be ensured that the entire vehicle maytravel in the pure fuel mode, thereby improving travelling mileage ofthe entire vehicle.

Embodiment 2

In some embodiments of the present invention, the control module 101 isconfigured to obtain an SOC (state of charge, also referred to asremaining power level) value of the power battery 3 and a speed V of thehybrid power automobile; and control, according to the SOC value of thepower battery 3 and the speed V of the hybrid power automobile, theauxiliary motor 5 to enter a power generation power adjustment mode, sothat the engine 1 runs in a preset optimal economical area. The powergeneration power adjustment mode is a mode of adjusting a powergeneration power of the engine, and in the power generation poweradjustment mode, the power generation power of the auxiliary motor 5 maybe adjusted by controlling the engine 1 to drive the auxiliary motor 5to perform power generation.

It should be noted that, the SOC value of the power battery 3 may becollected through a battery management system of the hybrid powerautomobile, and therefore the battery management system sends thecollected SOC value of the power battery 3 to the control module 101, sothat the control module 101 obtains the SOC value of the power battery3.

It should be further noted that, the preset optimal economical area ofthe engine 1 may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine 1, a horizontalcoordinate indicates a rotational speed of the engine 1, and a curve ais a fuel economy curve of the engine 1. An area corresponding to thefuel economy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine 1 arelocated on an optimal fuel economy curve of the engine, the engine islocated in the optimal economical area. Therefore, in this embodiment ofthe present invention, the control module 101 may enable, by controllingthe rotational speed and the output torque of the engine 1 to fall onthe fuel economy curve of the engine, for example, the curve a, theengine 1 to run in the preset optimal economical area.

Specifically, when the hybrid power automobile is travelling, the engine1 may output power to the wheels 7 of the hybrid power automobilethrough the clutch 6, and the engine 1 may further drive the auxiliarymotor 5 to perform power generation. Therefore, the output power of theengine mainly includes two parts, one part is output to the auxiliarymotor 5, that is, the power generation power for driving the auxiliarymotor 5 to perform power generation, and the other part is output to thewheels 7, that is, the drive power for driving the wheels 7.

When the engine 1 drives the auxiliary motor 5 to perform powergeneration, the control module 101 may first obtain the SOC value of thepower battery 3 and the speed of the hybrid power automobile, and thencontrol, according to the SOC value of the power battery 3 and the speedof the hybrid power automobile, the auxiliary motor 5 to enter the powergeneration power adjustment mode, so that the engine 1 operates in thepreset optimal economical area. In the power generation power adjustmentmode, the control module 101 may adjust the power generation power ofthe auxiliary motor 5 on the premise of enabling the engine 1 to operatein the preset optimal economical area.

Therefore, the engine 1 is enabled to operate in the preset optimaleconomical area, and because the engine 1 has lowest fuel consumptionand highest fuel economy in the preset optimal economical area, fuelconsumption of the engine 1 may be reduced, noise of the engine 1 may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor 5 has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel.

Further, according to an embodiment of the present invention, thecontrol module 101 configured to: when the SOC value of the powerbattery 3 is greater than a preset limit value M2 and is less than orequal to a first preset value M1, control, if the speed V of the hybridpower automobile is less than a first preset speed V1, the auxiliarymotor 5 to enter the power generation power adjustment mode.

The first preset value M1 may be a preset upper limit value of the SOCvalue of the power battery 3, for example, a value of determining tostop charging, and may be preferably 30%. The preset limit value may bea preset lower limit value of the SOC value of the power battery 3, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery 3 may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power battery 3is less than or equal to the preset limit value, the SOC value of thepower battery 3 falls within the first power level range. In this case,the power battery 3 performs only charging but does not performdischarging. When the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue, the SOC value of the power battery 3 falls within the secondpower level range. In this case, the power battery 3 has a chargingrequirement, that is, the power battery 3 may be actively charged. Whenthe SOC value of the power battery 3 is greater than the first presetvalue, the SOC value of the power battery 3 falls within the third powerlevel range. In this case, the power battery 3 may be not charged, thatis, the power battery 3 is not actively charged.

Specifically, after obtaining the SOC value of the power battery 3 andthe speed of the hybrid power automobile, the control module 101 maydetermine a range within which the SOC value of the power battery 3falls. If the SOC value of the power battery 3 falls within the secondpower level range, and the SOC value of the power battery 3 is greaterthan the preset limit value and is less than or equal to the firstpreset value, it indicates that the power battery 3 may be charged. Inthis case, the control module 101 further determines whether the speedof the hybrid power automobile is less than the first preset speed. Ifthe speed of the hybrid power automobile is less than the first presetspeed, the control module 101 controls the auxiliary motor 5 to enterthe power generation power adjustment mode. In this case, the speed ofthe hybrid power automobile is relatively low, a needed drive force isrelatively small, the power motor 2 is sufficient to drive the hybridpower automobile to travel, and the engine 1 may drive only theauxiliary motor 5 to perform power generation, but does not participatein drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is greater than the preset limit value M2 and is lessthan or equal to the first preset value M1, and the speed V of thehybrid power automobile is less than the first preset speed V1, obtainan entire vehicle requirement power P2 of the hybrid power automobile;and when the entire vehicle requirement power P2 is less than or equalto a maximum allowed power generation power Pmax of the auxiliary motor5, control the auxiliary motor 5 to enter the power generation poweradjustment mode.

Specifically, when the hybrid power automobile is travelling, if the SOCvalue of the power battery 3 is greater than the preset limit value M2and is less than or equal to the first preset value M1, and the speed Vof the hybrid power automobile is less than the first preset speed V1,that is, the speed of the hybrid power automobile is relatively low, thecontrol module 101 obtains the entire vehicle requirement power P2 ofthe hybrid power automobile; and controls, when the entire vehiclerequirement power P2 is less than or equal to the maximum allowed powergeneration power Pmax of the auxiliary motor 5, the auxiliary motor 5 toenter the power generation power adjustment mode.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is greater than the preset limit value and is less thanor equal to the first preset value M1, the speed V of the hybrid powerautomobile is less than the first preset speed V1, and the entirevehicle requirement power P2 is less than or equal to the maximumallowed power generation power Pmax of the auxiliary motor 5, obtain anaccelerator pedal depth D of the hybrid power automobile and an entirevehicle resistance F of the hybrid power automobile; and when theaccelerator pedal depth D is less than or equal to a first preset depthD1 and the entire vehicle resistance F of the hybrid power automobile isless than or equal to a first preset resistance F1, control theauxiliary motor 5 to enter the power generation power adjustment mode.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

Specifically, if the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue M1, the speed V of the hybrid power automobile is less than thefirst preset speed V1, and the entire vehicle requirement power P2 isless than or equal to the maximum allowed power generation power Pmax ofthe auxiliary motor 5, the control module 101 obtains the acceleratorpedal depth D of the hybrid power automobile and the entire vehicleresistance F of the hybrid power automobile in real time; and when theaccelerator pedal depth D is less than or equal to the first presetdepth D1 and the entire vehicle resistance F of the hybrid powerautomobile is less than or equal to the first preset resistance F1, thecontrol module 101 controls the auxiliary motor 5 to enter the powergeneration power adjustment mode.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

Correspondingly, when the SOC value of the power battery 3, the speed V,the accelerator pedal depth D and the entire vehicle resistance F of thehybrid power automobile do not satisfy the foregoing conditions, theengine 1 may participate in drive, and a specific operating processthereof is as follows:

According to an embodiment of the present invention, the control module101 is further configured to: when the SOC value of the power battery 3is less than the preset limit value, the speed of the hybrid powerautomobile is greater than or equal to the first preset speed, theentire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, the accelerator pedaldepth is greater than the first preset depth, or the entire vehicleresistance of the hybrid power automobile is greater than the firstpreset resistance, control the engine 1 to participate in drive.

To be specific, when the SOC value of the power battery 3 is less thanthe preset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor 5, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, thecontrol module 101 controls the engine 1 to participate in drive. Inthis case, the power battery 3 does not perform discharging again, theentire vehicle needs a relatively large drive force, the entire vehiclerequirement power is relatively large, the accelerator pedal depth isrelatively large or the entire vehicle resistance is also relativelylarge, the power motor 2 is insufficient to drive the hybrid powerautomobile to travel, and the engine 1 participates in drive to performsupplemental drive.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, the control module 101 is further configured to: whenthe entire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, control the engine 1 toparticipate in drive to enable the engine 1 to output power to wheelsthrough the clutch 6.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than the preset limit value M2,control the engine 1 to participate in drive to enable the engine 1 tooutput a drive force to the wheels 7 through the clutch 6. When the SOCvalue of the power battery 3 is less than or equal to the first presetvalue M1, the speed V of the hybrid power automobile is less than thefirst preset speed V1 and the accelerator pedal depth D is greater thanthe first preset depth D1, the control module 101 controls the engine 1to participate in drive to enable the engine 1 to output power to thewheels 7 through the clutch 6. When the SOC value of the power battery 3is less than or equal to the first preset value M1, the speed V of thehybrid power automobile is less than the first preset speed V1 and theresistance F of the hybrid power automobile is greater than the firstpreset resistance F1, the control module 101 controls the engine 1 toparticipate in drive to enable the engine 1 to output power to thewheels 7 through the clutch 6.

Specifically, when the engine 1 drives the auxiliary motor 5 to performpower generation and the power motor 2 outputs a drive force to thewheels 7 of the hybrid power automobile, the control module 101 obtainsthe SOC value of the power battery 3, the accelerator pedal depth D ofthe hybrid power automobile, the speed V and the entire vehicleresistance F in real time, and determines the SOC value of the powerbattery 3, the accelerator pedal depth D of the hybrid power automobile,the speed V and the entire vehicle resistance F.

First, when the SOC value of the power battery 3 is less than the presetlimit value M2, the control module 101 controls the engine 1 to outputpower to the wheels 7 through the clutch 6, so that the engine 1 and thepower motor 2 simultaneously participate in drive, and load of the powermotor 2 is reduced to reduce power consumption of the power battery 3,thereby ensuring that the engine 1 operates in the preset optimaleconomical area and preventing the SOC value of the power battery 3 fromquick decreasing.

Second, when the SOC value of the power battery 3 is less than or equalto the first preset value M1, the speed V of the hybrid power automobileis less than the first preset speed V1 and the accelerator pedal depth Dis greater than the first preset depth D1, the control module 101controls the engine 1 to output power to the wheels 7 through the clutch6, so that the engine 1 and the power motor 2 simultaneously participatein drive, and load of the power motor 2 is reduced to reduce powerconsumption of the power battery 3, thereby ensuring that the engine 1operates in the preset optimal economical area and preventing the SOCvalue of the power battery 3 from quick decreasing.

Third, when the SOC value of the power battery 3 is less than or equalto the first preset value M1, the speed V of the hybrid power automobileis less than the first preset speed V1 and the resistance F of thehybrid power automobile is greater than the first preset resistance F1,the control module 101 controls the engine 1 to output power to thewheels 7 through the clutch 6, so that the engine 1 and the power motor2 simultaneously participate in drive, and load of the power motor 2 isreduced to reduce power consumption of the power battery 3, therebyensuring that the engine 1 operates in the preset optimal economicalarea and preventing the SOC value of the power battery 3 from quickdecreasing.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine 1 to participate in drive toenable the engine 1 to output power to the wheels 7 through the clutch6.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module 101 isfurther configured to: when the SOC value of the power battery 3 isgreater than the first preset value, control the engine 1 not to drivethe auxiliary motor 5 to perform power generation. In this case, thepower battery 3 has an approximately full power level, and does not needto be charged, and the engine 1 does not drive the auxiliary motor 5 toperform power generation. To be specific, when the power battery 3 hasan approximately full power level, the engine 1 does not drive theauxiliary motor 5 to perform power generation, and therefore theauxiliary motor 5 does not charge the power battery 3.

Further, after the auxiliary motor 5 enters the power generation poweradjustment mode, the control module 101 may adjust the power generationpower of the auxiliary motor 5. A process of adjusting the powergeneration power of the control module 101 of this embodiment of thepresent invention is specifically described below.

According to an embodiment of the present invention, the control module101 is further configured to: after the auxiliary motor 5 enters thepower generation power adjustment mode, adjust a power generation powerP1 of the auxiliary motor 5 according to the entire vehicle requirementpower P2 of the hybrid power automobile and a charging power P3 of thepower battery 3.

According to an embodiment of the present invention, a formula ofadjusting the power generation power P1 of the auxiliary motor 5according to the entire vehicle requirement power P2 of the hybrid powerautomobile and the charging power P3 of the power battery is as follows:

P1=P2+P3, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor 5, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery 3, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices include the firstelectric appliance device 10 and the second electric appliance device30, that is, the electric appliance device power P21 may include powerneeded by the high-voltage electric appliance device and the low-voltageelectric appliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor 2, and the control module101 may obtain the entire vehicle drive power P11 according to a presetaccelerator-torsional moment curve of the power motor 2 and a rotationalspeed of the power motor 2, where the preset accelerator-torsionalmoment curve may be determined during power matching of the hybrid powerautomobile. Additionally, the control module 101 may obtain the electricappliance device power P21 in real time according to electric appliancedevices running on the entire vehicle, for example, calculate theelectric appliance device power P21 through DC consumption on a bus.Moreover, the control module 101 may obtain the charging power P3 of thepower battery 3 according to the SOC value of the power battery 3.Assuming that the entire vehicle drive power P11 obtained in real timeis equal to b1 kw, the electric appliance device power P21 is equal tob2 kw, and the charging power P3 of the power battery 3 is equal to b3kw, the power generation power of the auxiliary motor 5 is equal tob1+b2+b3.

Specifically, when the hybrid power automobile is travelling, thecontrol module 101 may obtain the charging power P3 of the power battery3, the entire vehicle drive power P11 and the electric appliance devicepower P21, and use a sum of the charging power P3 of the power battery3, the entire vehicle drive power P11 and the electric appliance devicepower P21 as the power generation power P1 of the auxiliary motor 5.Therefore, the control module 101 may adjust the power generation powerof the auxiliary motor 5 according to the calculated P1 value. Forexample, the control module 101 may control the output torque and therotational speed of the engine 1 according to the calculated P1 value,so as to adjust the power for the engine 1 to drive the auxiliary motor5 to perform power generation.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: obtain an SOC value changerate of the power battery 3, and adjust the power generation power P1 ofthe auxiliary motor 5 according to a relationship between the entirevehicle requirement power P2 and a minimum output power Pmincorresponding to the optimal economical area of the engine 1, and theSOC value change rate of the power battery.

It should be understood that, the control module 101 may obtain the SOCvalue change rate of the power battery 3 according to the SOC value ofthe power battery 3, for example, collect the SOC value of the powerbattery 3 once at each time interval t. In this way, a ratio of adifference between a current SOC value and a former SOC value of thepower battery 3 to the time interval t may be used as the SOC valuechange rate of the power battery 3.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After determining theminimum output power Pmin corresponding to the optimal economical areaof the engine, the control module 101 may adjust the power generationpower of the auxiliary motor 5 according to the relationship between theentire vehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine 1, and theSOC value change rate of the power battery 3.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine 1 may perform only power generation but does not participatein drive, and because the engine does not participate in drive, theclutch does not need to be used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness, so as to maintain low-speed electric balance andlow-speed smoothness of the entire vehicle and improve performance ofthe entire vehicle.

A specific adjusting manner in which after the auxiliary motor 5 entersthe power generation power adjustment mode, the control module 101adjusts the power generation power of the auxiliary motor 5 according tothe relationship between the entire vehicle requirement power P2 and theminimum output power Pmin corresponding to the optimal economical areaof the engine 1, and the SOC value change rate of the power battery 3 isfurther described below.

Specifically, when the engine 1 drives the auxiliary motor 5 to performpower generation and the power motor 2 outputs a drive force to thewheels 7 of the hybrid power automobile, the entire vehicle drive powerP11 and the electric appliance device power P21 are obtained in realtime, so as to obtain the entire vehicle requirement power P2 of thehybrid power automobile, and the control module 101 determines theentire vehicle requirement power P2 of the hybrid power automobile,where the entire vehicle requirement power P2 may satisfy the followingthree cases.

In a first case, the entire vehicle requirement power P2 is less thanthe minimum output power Pmin corresponding to the optimal economicalarea of the engine 1; in a second case, the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor 5; and in a third case, the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor 5.

In an embodiment of the first case, when the entire vehicle requirementpower P2 is less than the minimum output power Pmin corresponding to theoptimal economical area of the engine 1, the control module 101 obtainsthe charging power P3 of the power battery 3 according to the SOC valuechange rate of the power battery 3, and determines whether the chargingpower P3 of the power battery 3 is less than a difference between theminimum output power Pmin and the entire vehicle requirement power P2.If the charging power P3 of the power battery 3 is less than thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, the control module 101 controls the engine 1 toperform power generation at the minimum output power Pmin to adjust thepower generation power P1 of the auxiliary motor 5; or if the chargingpower P3 of the power battery 3 is greater than or equal to thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, the control module 101 obtains an output power ofthe engine 1 in the preset optimal economical area according to a sum ofthe charging power P3 of the power battery 3 and the entire vehiclerequirement power P2, and controls the engine to perform powergeneration at the obtained output power to adjust the power generationpower P1 of the auxiliary motor 5.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery 3 and the charging power P3 ofthe power battery 3 may be pre-stored in the control module 101.Therefore, after obtaining an SOC value change rate of the power battery3, the control module 101 may obtain a corresponding charging power P3of the power battery 3 by performing matching on the first relationshiptable. The SOC value change rate of the power battery 3 and the chargingpower P3 of the power battery 3 satisfy a relationship shown in Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power P3 of the power B1 B2 B3 B4 B5 battery 3

It is learned from Table 1 that, when an SOC value change rate obtainedby the control module 101 is A1, an obtained corresponding chargingpower P3 of the power battery 3 is B1; when an SOC value change rateobtained by the control module 101 is A2, an obtained correspondingcharging power P3 of the power battery 3 is B2; when an SOC value changerate obtained by the control module 101 is A3, an obtained correspondingcharging power P3 of the power battery 3 is B3; when an SOC value changerate obtained by the control module 101 is A4, an obtained correspondingcharging power P3 of the power battery 3 is B4; and when an SOC valuechange rate obtained by the control module 101 is A5, an obtainedcorresponding charging power P3 of the power battery 3 is B5.

Specifically, after the auxiliary motor 5 enters the power generationpower adjustment mode, the control module 101 obtains the entire vehicledrive power P11 and the electric appliance device power P21 in realtime, so as to obtain the entire vehicle requirement power P2 of thehybrid power automobile, and determine the entire vehicle requirementpower P2 of the hybrid power automobile. When the entire vehiclerequirement power P2 is less than the minimum output power Pmincorresponding to the optimal economical area of the engine 1, thecontrol module 101 may obtain the charging power P3 of the power battery3 according to the SOC value change rate of the power battery 3, anddetermine whether the charging power P3 of the power battery 3 is lessthan the difference between the minimum output power Pmin and the entirevehicle requirement power P2.

When the entire vehicle requirement power P2 is less than the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1, if the charging power P3 of the power battery 3 is less thanthe difference between the minimum output power Pmin and the entirevehicle requirement power P2, that is, P3<Pmin−P2, the control module101 controls the engine 1 to perform power generation at the minimumoutput power Pmin to adjust the power generation power of the auxiliarymotor 1. If the charging power P3 of the power battery 3 is greater thanor equal to the difference between the minimum output power Pmin and theentire vehicle requirement power P2, that is, P3≤Pmin−P2, the controlmodule 101 obtains the output power of the engine 1 in the presetoptimal economical area according to the sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to adjust the power generation power of the auxiliary motor 5.

Therefore, when the entire vehicle requirement power P2 is less than theminimum output power Pmin corresponding to the optimal economical areaof the engine 1, the control module 101 obtains the power generationpower of the engine 1 according to the relationship between the chargingpower P3 of the power battery 3 and the difference between the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1 and the entire vehicle requirement power P2, so that the engine1 runs in the preset optimal economical area, and the engine 1 performsonly power generation but does not participate in drive, therebyreducing fuel consumption of the engine, and reducing noise of theengine.

In an embodiment of the second case, when the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor 5, the control module 101 obtains the charging power P3of the power battery 3 according to the SOC value change rate of thepower battery 3, obtains an output power of the engine 1 in the presetoptimal economical area according to a sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to adjust the power generation power P1 of the auxiliary motor 5.

Specifically, when the entire vehicle requirement power P2 is greaterthan or equal to the minimum output power Pmin corresponding to theoptimal economical area of the engine 1 and is less than the maximumallowed power generation power Pmax of the auxiliary motor 5, whencontrolling the engine 1 to operate in the preset optimal economicalarea, the control module 101 further obtains the charging power P3 ofthe power battery 3 according to the SOC value change rate of the powerbattery 3, and obtains the output power of the engine 1 in the presetoptimal economical area according to the sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, wherethe obtained output power is equal to P3+P2. Then, the control module101 controls the engine 1 to perform power generation at the obtainedoutput power to adjust the power generation power P1 of the auxiliarymotor 5, thereby increasing the SOC value of the power battery 3, andenabling the engine 1 to operate in the preset optimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanor equal to the minimum output power Pmin corresponding to the optimaleconomical area of the engine 1 and is less than the maximum allowedpower generation power Pmax of the auxiliary motor 5, the control module101 obtains the output power of the engine 1 according to the sum of thecharging power P3 of the power battery 3 and the entire vehiclerequirement power P2, so that the engine 1 runs in the preset optimaleconomical area, and the engine 1 performs only power generation butdoes not participate in drive, thereby reducing fuel consumption of theengine, and reducing noise of the engine.

In an embodiment of the third case, when the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor 5, the control module 101 further controls theengine 1 to participate in drive to enable the engine 1 to output powerto the wheels 7 through the clutch 6.

Specifically, when the entire vehicle requirement power P2 is greaterthan the maximum allowed power generation power Pmax of the auxiliarymotor 5, that is, the entire vehicle requirement power P2 of the hybridpower automobile is greater than the power generation power P1 of theauxiliary motor 5, the control module 101 further controls the engine 1to output a drive force to the wheels 7 through the clutch 6 to enablethe engine 1 to participate in drive. Therefore, the engine 1 undertakesa part of a drive power P, so as to reduce a requirement of theauxiliary motor 5 on the power generation power P1, so that the engine 1operates in the preset optimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanthe maximum allowed power generation power Pmax of the auxiliary motor5, the power battery 3 discharges outward to supply power to the powermotor 2. In this case, the control module 101 controls the engine 1 andthe power motor 2 to simultaneously output power to the wheels 7 of thehybrid power automobile, so that the engine 1 operates in the presetoptimal economical area.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

To sum up, according to the power system of a hybrid power automobileproposed in this embodiment of the present invention, the engine outputspower to the wheels of the hybrid power automobile through the clutch,the power motor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, theauxiliary motor performs power generation under driving of the engine,and the control module obtains the SOC value of the power battery andthe speed of the hybrid power automobile, and controls, according to theSOC value of the power battery and the speed of the hybrid powerautomobile, the auxiliary motor to enter the power generation poweradjustment mode, so that the engine runs in the preset optimaleconomical area, thereby reducing fuel consumption of the engine,improving running economy of the entire vehicle, reducing noise of theengine, implementing a plurality of drive modes, maintaining low-speedelectric balance and low-speed smoothness of the entire vehicle, andimproving performance of the entire vehicle.

Embodiment 3

In some embodiments of the present invention, the power system of ahybrid power automobile further includes a control module 101. When thehybrid power automobile is travelling, the control module 101 isconfigured to obtain an SOC (state of charge, also referred to asremaining power level) value of the power battery 3 and a speed V of thehybrid power automobile, control the power generation power P1 of theauxiliary motor 5 according to the SOC value of the power battery 3 andthe speed V of the hybrid power automobile, and obtain a powergeneration power P0 of the engine 1 according to the power generationpower P1 of the auxiliary motor 5 to control the engine 1 to run in thepreset optimal economical area.

It should be noted that, the SOC value of the power battery 3 may becollected through a battery management system of the hybrid powerautomobile, and therefore the battery management system sends thecollected SOC value of the power battery 3 to the control module 101, sothat the control module 101 obtains the SOC value of the power battery3.

It should be further noted that, the preset optimal economical area ofthe engine 1 may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine 1, a horizontalcoordinate indicates a rotational speed of the engine 1, and a curve ais a fuel economy curve of the engine 1. An area corresponding to thefuel economy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine 1 arelocated on an optimal fuel economy curve of the engine, the engine islocated in the optimal economical area. Therefore, in this embodiment ofthe present invention, the control module 101 may enable, by controllingthe rotational speed and the output torque of the engine 1 to fall onthe fuel economy curve of the engine, for example, the curve a, theengine 1 to run in the preset optimal economical area.

Specifically, when the hybrid power automobile is travelling, the engine1 may output power to the wheels 7 of the hybrid power automobilethrough the clutch 6, and the engine 1 may further drive the auxiliarymotor 5 to perform power generation. Therefore, the output power of theengine mainly includes two parts, one part is output to the auxiliarymotor 5, that is, the power generation power for driving the auxiliarymotor 5 to perform power generation, and the other part is output to thewheels 7, that is, the drive power for driving the wheels 7.

When the engine 1 drives the auxiliary motor 5 to perform powergeneration, the control module 101 may first obtain the SOC value of thepower battery 3 and the speed of the hybrid power automobile, thencontrol the power generation power P1 of the auxiliary motor 5 accordingto the SOC value of the power battery 3 and the speed of the hybridpower automobile, and obtain the power generation power P0 of the engine1 according to the power generation power P1 of the auxiliary motor 5 tocontrol the engine 1 to run in the preset optimal economical area. Thecontrol module 101 may determine, on the premise of enabling the engine1 to operate in the preset optimal economical area, power for the engine1 to drive the auxiliary motor 5 to perform power generation, therebyadjusting the power generation power P1 of the auxiliary motor 5.

Therefore, the engine 1 is enabled to operate in the preset optimaleconomical area, and because the engine 1 has lowest fuel consumptionand highest fuel economy in the preset optimal economical area, fuelconsumption of the engine 1 may be reduced, noise of the engine 1 may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor 5 has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel.

Further, according to an embodiment of the present invention, thecontrol module 101 configured to: when the SOC value of the powerbattery 3 is greater than a preset limit value M2 and is less than orequal to a first preset value M1, control the power generation power P1of the auxiliary motor 5 if the speed V of the hybrid power automobileis less than a first preset speed V1.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery 3, for example, a value of determining tostop charging, and may be preferably 30%. The preset limit value may bea preset lower limit value of the SOC value of the power battery 3, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery 3 may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power battery 3is less than or equal to the preset limit value, the SOC value of thepower battery 3 falls within the first power level range. In this case,the power battery 3 performs only charging but does not performdischarging. When the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue, the SOC value of the power battery 3 falls within the secondpower level range. In this case, the power battery 3 has a chargingrequirement, that is, the power battery 3 may be actively charged. Whenthe SOC value of the power battery 3 is greater than the first presetvalue, the SOC value of the power battery 3 falls within the third powerlevel range. In this case, the power battery 3 may be not charged, thatis, the power battery 3 is not actively charged.

Specifically, after obtaining the SOC value of the power battery 3 andthe speed of the hybrid power automobile, the control module 101 maydetermine a range within which the SOC value of the power battery 3falls. If the SOC value of the power battery 3 falls within the secondpower level range, and the SOC value of the power battery 3 is greaterthan the preset limit value and is less than or equal to the firstpreset value, it indicates that the power battery 3 may be charged. Inthis case, the control module 101 further determines whether the speedof the hybrid power automobile is less than the first preset speed. Ifthe speed of the hybrid power automobile is less than the first presetspeed, the control module 101 controls the power generation power P1 ofthe auxiliary motor 5. In this case, the speed of the hybrid powerautomobile is relatively low, a needed drive force is relatively small,the power motor 2 is sufficient to drive the hybrid power automobile totravel, and the engine 1 may drive only the auxiliary motor 5 to performpower generation, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is greater than the preset limit value M2 and is lessthan or equal to the first preset value M1, and the speed V of thehybrid power automobile is less than the first preset speed V1, obtainan entire vehicle requirement power P2 of the hybrid power automobile;and when the entire vehicle requirement power P2 is less than or equalto a maximum allowed power generation power Pmax of the auxiliary motor5, control the power generation power P1 of the auxiliary motor 5.

Specifically, when the hybrid power automobile is travelling, if the SOCvalue of the power battery 3 is greater than the preset limit value M2and is less than or equal to the first preset value M1, and the speed Vof the hybrid power automobile is less than the first preset speed V1,that is, the speed of the hybrid power automobile is relatively low, thecontrol module 101 obtains the entire vehicle requirement power P2 ofthe hybrid power automobile; and controls the power generation power P1of the auxiliary motor 5 when the entire vehicle requirement power P2 isless than or equal to the maximum allowed power generation power Pmax ofthe auxiliary motor 5.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is greater than the preset limit value and is less thanor equal to the first preset value M1, the speed V of the hybrid powerautomobile is less than the first preset speed V1, and the entirevehicle requirement power P2 is less than or equal to the maximumallowed power generation power Pmax of the auxiliary motor 5, obtain anaccelerator pedal depth D of the hybrid power automobile and an entirevehicle resistance F of the hybrid power automobile; and when theaccelerator pedal depth D is less than or equal to a first preset depthD1 and the entire vehicle resistance F of the hybrid power automobile isless than or equal to a first preset resistance F1, control the powergeneration power P1 of the auxiliary motor 5.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

Specifically, if the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue M1, the speed V of the hybrid power automobile is less than thefirst preset speed V1, and the entire vehicle requirement power P2 isless than or equal to the maximum allowed power generation power Pmax ofthe auxiliary motor 5, the control module 101 obtains the acceleratorpedal depth D of the hybrid power automobile and the entire vehicleresistance F of the hybrid power automobile in real time; and when theaccelerator pedal depth D is less than or equal to the first presetdepth D1 and the entire vehicle resistance F of the hybrid powerautomobile is less than or equal to the first preset resistance F1, thecontrol module 101 controls the power generation power P1 of theauxiliary motor 5.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

According to an embodiment of the present invention, the control module101 is further configured to: when controlling the engine 1 toindividually drive the auxiliary motor 5 to perform power generation andcontrolling the power motor 2 to output a drive force alone, obtain thepower generation power of the engine 1 according to the followingformula:

P0=P1/η/ζ

where P0 is the power generation power of the engine 1, P1 is the powergeneration power of the auxiliary motor 5, η is belt transmissionefficiency, and ζ is efficiency of the auxiliary motor 5.

To be specific, if the engine 1 may perform only power generation butdoes not participate in drive, the control module 101 may calculate thepower generation power P0 of the engine 1 according to the powergeneration power of the auxiliary motor 5, the belt transmissionefficiency η and the efficiency ζ of the auxiliary motor 5, and controlthe engine 1 to drive the auxiliary motor 5 at the obtained powergeneration power P0 to perform power generation, so as to control thepower generation power of the auxiliary motor 5.

Correspondingly, when the SOC value of the power battery 3, the speed V,the accelerator pedal depth D and the entire vehicle resistance F of thehybrid power automobile do not satisfy the foregoing conditions, theengine 1 may participate in drive, and a specific operating processthereof is as follows:

According to an embodiment of the present invention, the control module101 is further configured to: when the SOC value of the power battery 3is less than the preset limit value, the speed of the hybrid powerautomobile is greater than or equal to the first preset speed, theentire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, the accelerator pedaldepth is greater than the first preset depth, or the entire vehicleresistance of the hybrid power automobile is greater than the firstpreset resistance, control the engine 1 to participate in drive.

To be specific, when the SOC value of the power battery 3 is less thanthe preset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor 5, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, thecontrol module 101 controls the engine 1 to participate in drive. Inthis case, the power battery 3 does not perform discharging again, theentire vehicle needs a relatively large drive force, the entire vehiclerequirement power is relatively large, the accelerator pedal depth isrelatively large or the entire vehicle resistance is also relativelylarge, the power motor 2 is insufficient to drive the hybrid powerautomobile to travel, and the engine 1 participates in drive to performsupplemental drive.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, the control module 101 is further configured to: whenthe entire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, control the engine 1 toparticipate in drive to enable the engine 1 to output power to wheelsthrough the clutch 6.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than the preset limit value M2,control the engine 1 to participate in drive to enable the engine 1 tooutput a drive force to the wheels 7 through the clutch 6. When the SOCvalue of the power battery 3 is less than or equal to the first presetvalue M1, the speed V of the hybrid power automobile is less than thefirst preset speed V1 and the accelerator pedal depth D is greater thanthe first preset depth D1, the control module 101 controls the engine 1to participate in drive to enable the engine 1 to output power to thewheels 7 through the clutch 6. When the SOC value of the power battery 3is less than or equal to the first preset value M1, the speed V of thehybrid power automobile is less than the first preset speed V1 and theresistance F of the hybrid power automobile is greater than the firstpreset resistance F1, the control module 101 controls the engine 1 toparticipate in drive to enable the engine 1 to output power to thewheels 7 through the clutch 6.

Specifically, when the engine 1 drives the auxiliary motor 5 to performpower generation and the power motor 2 outputs a drive force to thewheels 7 of the hybrid power automobile, the control module 101 obtainsthe SOC value of the power battery 3, the accelerator pedal depth D ofthe hybrid power automobile, the speed V and the entire vehicleresistance F in real time, and determines the SOC value of the powerbattery 3, the accelerator pedal depth D of the hybrid power automobile,the speed V and the entire vehicle resistance F.

First, when the SOC value of the power battery 3 is less than the presetlimit value M2, the control module 101 controls the engine 1 to outputpower to the wheels 7 through the clutch 6, so that the engine 1 and thepower motor 2 simultaneously participate in drive, and load of the powermotor 2 is reduced to reduce power consumption of the power battery 3,thereby ensuring that the engine 1 operates in the preset optimaleconomical area and preventing the SOC value of the power battery 3 fromquick decreasing.

Second, when the SOC value of the power battery 3 is less than or equalto the first preset value M1, the speed V of the hybrid power automobileis less than the first preset speed V1 and the accelerator pedal depth Dis greater than the first preset depth D1, the control module 101controls the engine 1 to output power to the wheels 7 through the clutch6, so that the engine 1 and the power motor 2 simultaneously participatein drive, and load of the power motor 2 is reduced to reduce powerconsumption of the power battery 3, thereby ensuring that the engine 1operates in the preset optimal economical area and preventing the SOCvalue of the power battery 3 from quick decreasing.

Third, when the SOC value of the power battery 3 is less than or equalto the first preset value M1, the speed V of the hybrid power automobileis less than the first preset speed V1 and the resistance F of thehybrid power automobile is greater than the first preset resistance F1,the control module 101 controls the engine 1 to output power to thewheels 7 through the clutch 6, so that the engine 1 and the power motor2 simultaneously participate in drive, and load of the power motor 2 isreduced to reduce power consumption of the power battery 3, therebyensuring that the engine 1 operates in the preset optimal economicalarea and preventing the SOC value of the power battery 3 from quickdecreasing.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine 1 to participate in drive toenable the engine 1 to output power to the wheels 7 through the clutch6.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module 101 isfurther configured to: when the SOC value of the power battery 3 isgreater than the first preset value, control the engine 1 not to drivethe auxiliary motor 5 to perform power generation. In this case, thepower battery 3 has an approximately full power level, and does not needto be charged, and the engine 1 does not drive the auxiliary motor 5 toperform power generation. To be specific, when the power battery 3 hasan approximately full power level, the engine 1 does not drive theauxiliary motor 5 to perform power generation, and therefore theauxiliary motor 5 does not charge the power battery 3.

Further, after the auxiliary motor 5 enters the power generation poweradjustment mode, the control module 101 may control the power generationpower of the auxiliary motor 5. A process of controlling the powergeneration power of the control module 101 of this embodiment of thepresent invention is specifically described below.

According to an embodiment of the present invention, the control module101 is further configured to: control the power generation power P1 ofthe auxiliary motor 5 according to the entire vehicle requirement powerP2 of the hybrid power automobile and the charging power P3 of the powerbattery 3.

According to an embodiment of the present invention, a formula ofcontrolling the power generation power P1 of the auxiliary motor 5according to the entire vehicle requirement power P2 of the hybrid powerautomobile and the charging power P3 of the power battery is as follows:

P1=P2+P3, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor 5, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery 3, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices include the firstelectric appliance device 10 and the second electric appliance device30, that is, the electric appliance device power P21 may include powerneeded by the high-voltage electric appliance device and the low-voltageelectric appliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor 2, and the control module101 may obtain the entire vehicle drive power P11 according to a presetaccelerator-torsional moment curve of the power motor 2 and a rotationalspeed of the power motor 2, where the preset accelerator-torsionalmoment curve may be determined during power matching of the hybrid powerautomobile. Additionally, the control module 101 may obtain the electricappliance device power P21 in real time according to electric appliancedevices running on the entire vehicle, for example, calculate theelectric appliance device power P21 through DC consumption on a bus.Moreover, the control module 101 may obtain the charging power P3 of thepower battery 3 according to the SOC value of the power battery 3.Assuming that the entire vehicle drive power P11 obtained in real timeis equal to b1 kw, the electric appliance device power P21 is equal tob2 kw, and the charging power P3 of the power battery 3 is equal to b3kw, the power generation power of the auxiliary motor 5 is equal tob1+b2+b3.

Specifically, when the hybrid power automobile is travelling, thecontrol module 101 may obtain the charging power P3 of the power battery3, the entire vehicle drive power P11 and the electric appliance devicepower P21, and use a sum of the charging power P3 of the power battery3, the entire vehicle drive power P11 and the electric appliance devicepower P21 as the power generation power P1 of the auxiliary motor 5.Therefore, the control module 101 may control the power generation powerof the auxiliary motor 5 according to the calculated P1 value. Forexample, the control module 101 may control the output torque and therotational speed of the engine 1 according to the calculated P1 value,so as to control the power for the engine 1 to drive the auxiliary motor5 to perform power generation.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: obtain an SOC value changerate of the power battery 3, and control the power generation power P1of the auxiliary motor 5 according to a relationship between the entirevehicle requirement power P2 and a minimum output power Pmincorresponding to the optimal economical area of the engine 1, and theSOC value change rate of the power battery.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After determining theminimum output power Pmin corresponding to the optimal economical areaof the engine, the control module 101 may control the power generationpower of the auxiliary motor 5 according to the relationship between theentire vehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine 1, and theSOC value change rate of the power battery 3.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine 1 may perform only power generation but does not participatein drive, and because the engine does not participate in drive, theclutch does not need to be used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness, so as to maintain low-speed electric balance andlow-speed smoothness of the entire vehicle and improve performance ofthe entire vehicle.

A specific adjusting manner in which the control module 101 controls thepower generation power of the auxiliary motor 5 according to therelationship between the entire vehicle requirement power P2 and theminimum output power Pmin corresponding to the optimal economical areaof the engine 1, and the SOC value change rate of the power battery 3 isfurther described below.

Specifically, when the engine 1 drives the auxiliary motor 5 to performpower generation and the power motor 2 outputs a drive force to thewheels 7 of the hybrid power automobile, the entire vehicle drive powerP11 and the electric appliance device power P21 are obtained in realtime, so as to obtain the entire vehicle requirement power P2 of thehybrid power automobile, and the control module 101 determines theentire vehicle requirement power P2 of the hybrid power automobile,where the entire vehicle requirement power P2 may satisfy the followingthree cases.

In a first case, the entire vehicle requirement power P2 is less thanthe minimum output power Pmin corresponding to the optimal economicalarea of the engine 1; in a second case, the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor 5; and in a third case, the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor 5.

In an embodiment of the first case, when the entire vehicle requirementpower P2 is less than the minimum output power Pmin corresponding to theoptimal economical area of the engine 1, the control module 101 obtainsthe charging power P3 of the power battery 3 according to the SOC valuechange rate of the power battery 3, and determines whether the chargingpower P3 of the power battery 3 is less than the difference between theminimum output power Pmin and the entire vehicle requirement power P2.If the charging power P3 of the power battery 3 is less than thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, the control module 101 controls the engine 1 toperform power generation at the minimum output power Pmin to control thepower generation power P1 of the auxiliary motor 5; or if the chargingpower P3 of the power battery 3 is greater than or equal to thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, the control module 101 obtains an output power ofthe engine 1 in the preset optimal economical area according to a sum ofthe charging power P3 of the power battery 3 and the entire vehiclerequirement power P2, and controls the engine to perform powergeneration at the obtained output power to control the power generationpower P1 of the auxiliary motor 5.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery 3 and the charging power P3 ofthe power battery 3 may be pre-stored in the control module 101.Therefore, after obtaining an SOC value change rate of the power battery3, the control module 101 may obtain a corresponding charging power P3of the power battery 3 by performing matching on the first relationshiptable. The SOC value change rate of the power battery 3 and the chargingpower P3 of the power battery 3 satisfy a relationship shown in Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power P3 of the power B1 B2 B3 B4 B5 battery 3

It is learned from Table 1 that, when an SOC value change rate obtainedby the control module 101 is A1, an obtained corresponding chargingpower P3 of the power battery 3 is B1; when an SOC value change rateobtained by the control module 101 is A2, an obtained correspondingcharging power P3 of the power battery 3 is B2; when an SOC value changerate obtained by the control module 101 is A3, an obtained correspondingcharging power P3 of the power battery 3 is B3; when an SOC value changerate obtained by the control module 101 is A4, an obtained correspondingcharging power P3 of the power battery 3 is B4; and when an SOC valuechange rate obtained by the control module 101 is A5, an obtainedcorresponding charging power P3 of the power battery 3 is B5.

Specifically, when performing power generation power control on theauxiliary motor 5, the control module 101 obtains the entire vehicledrive power P11 and the electric appliance device power P21 in realtime, so as to obtain the entire vehicle requirement power P2 of thehybrid power automobile, and determine the entire vehicle requirementpower P2 of the hybrid power automobile. When the entire vehiclerequirement power P2 is less than the minimum output power Pmincorresponding to the optimal economical area of the engine 1, thecontrol module 101 may obtain the charging power P3 of the power battery3 according to the SOC value change rate of the power battery 3, anddetermine whether the charging power P3 of the power battery 3 is lessthan or equal to the difference between the minimum output power Pminand the entire vehicle requirement power P2.

When the entire vehicle requirement power P2 is less than the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1, if the charging power P3 of the power battery 3 is less thanthe difference between the minimum output power Pmin and the entirevehicle requirement power P2, that is, P3<Pmin−P2, the control module101 controls the engine 1 to perform power generation at the minimumoutput power Pmin to control the power generation power of the auxiliarymotor 1. If the charging power P3 of the power battery 3 is greater thanor equal to the difference between the minimum output power Pmin and theentire vehicle requirement power P2, that is, P3≤Pmin−P2, the controlmodule 101 obtains the output power of the engine 1 in the presetoptimal economical area according to the sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to control the power generation power of the auxiliary motor 5.

Therefore, when the entire vehicle requirement power P2 is less than theminimum output power Pmin corresponding to the optimal economical areaof the engine 1, the control module 101 obtains the power generationpower of the engine 1 according to the relationship between the chargingpower P3 of the power battery 3 and the difference between the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1 and the entire vehicle requirement power P2, so that the engine1 runs in the preset optimal economical area, and the engine 1 performsonly power generation but does not participate in drive, therebyreducing fuel consumption of the engine, and reducing noise of theengine.

In an embodiment of the second case, when the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor 5, the control module 101 obtains the charging power P3of the power battery 3 according to the SOC value change rate of thepower battery 3, obtains an output power of the engine 1 in the presetoptimal economical area according to a sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to control the power generation power P1 of the auxiliary motor 5.

Specifically, when the entire vehicle requirement power P2 is greaterthan or equal to the minimum output power Pmin corresponding to theoptimal economical area of the engine 1 and is less than the maximumallowed power generation power Pmax of the auxiliary motor 5, whencontrolling the engine 1 to operate in the preset optimal economicalarea, the control module 101 further obtains the charging power P3 ofthe power battery 3 according to the SOC value change rate of the powerbattery 3, and obtains the output power of the engine 1 in the presetoptimal economical area according to the sum of the charging power P3 ofthe power battery 3 and the entire vehicle requirement power P2, wherethe obtained output power is equal to P3+P2. Then, the control module101 controls the engine 1 to perform power generation at the obtainedoutput power to control the power generation power P1 of the auxiliarymotor 5, thereby increasing the SOC value of the power battery 3, andenabling the engine 1 to operate in the preset optimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanor equal to the minimum output power Pmin corresponding to the optimaleconomical area of the engine 1 and is less than the maximum allowedpower generation power Pmax of the auxiliary motor 5, the control module101 obtains the output power of the engine 1 according to the sum of thecharging power P3 of the power battery 3 and the entire vehiclerequirement power P2, so that the engine 1 runs in the preset optimaleconomical area, and the engine 1 performs only power generation butdoes not participate in drive, thereby reducing fuel consumption of theengine, and reducing noise of the engine.

In an embodiment of the third case, when the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor 5, the control module 101 further controls theengine 1 to participate in drive to enable the engine 1 to output powerto the wheels 7 through the clutch 6.

Specifically, when the entire vehicle requirement power P2 is greaterthan the maximum allowed power generation power Pmax of the auxiliarymotor 5, that is, the entire vehicle requirement power P2 of the hybridpower automobile is greater than the power generation power P1 of theauxiliary motor 5, the control module 101 further controls the engine 1to output a drive force to the wheels 7 through the clutch 6 to enablethe engine 1 to participate in drive. Therefore, the engine 1 undertakesa part of a drive power P, so as to reduce a requirement of theauxiliary motor 5 on the power generation power P1, so that the engine 1operates in the preset optimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanthe maximum allowed power generation power Pmax of the auxiliary motor5, the power battery 3 discharges outward to supply power to the powermotor 2. In this case, the control module 101 controls the power motor 2to output power to the wheels 7 of the hybrid power automobile, so thatthe engine 1 operates in the preset optimal economical area.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

To sum up, according to the power system of a hybrid power automobileproposed in this embodiment of the present invention, the engine outputspower to the wheels of the hybrid power automobile through the clutch,the power motor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, theauxiliary motor performs power generation under driving of the engine,and the control module obtains the SOC value of the power battery andthe speed of the hybrid power automobile, and controls, according to theSOC value of the power battery and the speed of the hybrid powerautomobile, the auxiliary motor to enter the power generation poweradjustment mode, so that the engine runs in the preset optimaleconomical area, thereby reducing fuel consumption of the engine,improving running economy of the entire vehicle, reducing noise of theengine, implementing a plurality of drive modes, maintaining low-speedelectric balance and low-speed smoothness of the entire vehicle, andimproving performance of the entire vehicle.

Embodiment 4

In some embodiments of the present invention, the control module 101 isconfigured to obtain an SOC (state of charge, also referred to asremaining power level) value of the power battery 3, an SOC value of thelow-voltage storage battery 20 and a speed of the hybrid powerautomobile; and control, according to the SOC value of the power battery3 and the speed of the hybrid power automobile, the auxiliary motor 5 toenter the power generation power adjustment mode, so that the engine 1runs in the preset optimal economical area. After the auxiliary motor 5enters the power generation power adjustment mode, the control module101 is further configured to adjust the power generation power of theauxiliary motor 5 according to the SOC value of the low-voltage storagebattery 20. The power generation power adjustment mode is a mode ofadjusting a power generation power of the engine, and in the powergeneration power adjustment mode, the power generation power of theauxiliary motor 5 may be adjusted by controlling the engine 1 to drivethe auxiliary motor 5 to perform power generation.

It should be noted that, the SOC value of the power battery 3 and theSOC value of the low-voltage storage battery 20 may be collected througha battery management system of the hybrid power automobile, andtherefore the battery management system sends the SOC value of the powerbattery 3 and the SOC value of the low-voltage storage battery 20 thatare collected to the control module 101, so that the control module 101obtains the SOC value of the power battery 3 and the SOC value of thelow-voltage storage battery 20.

It should be further noted that, the preset optimal economical area ofthe engine 1 may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine 1, a horizontalcoordinate indicates a rotational speed of the engine 1, and a curve ais a fuel economy curve of the engine 1. An area corresponding to thefuel economy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine 1 arelocated on an optimal fuel economy curve of the engine, the engine islocated in the optimal economical area. Therefore, in this embodiment ofthe present invention, the control module 101 may enable, by controllingthe rotational speed and the output torque of the engine 1 to fall onthe fuel economy curve of the engine, for example, the curve a, theengine 1 to run in the preset optimal economical area.

Specifically, when the hybrid power automobile is travelling, the engine1 may output power to the wheels 7 of the hybrid power automobilethrough the clutch 6, and the engine 1 may further drive the auxiliarymotor 5 to perform power generation. Therefore, the output power of theengine mainly includes two parts, one part is output to the auxiliarymotor 5, that is, the power generation power for driving the auxiliarymotor 5 to perform power generation, and the other part is output to thewheels 7, that is, the drive power for driving the wheels 7.

When the engine 1 drives the auxiliary motor 5 to perform powergeneration, the control module 101 may first obtain the SOC value of thepower battery 3 and the speed of the hybrid power automobile, and thencontrol, according to the SOC value of the power battery 3 and the speedof the hybrid power automobile, the auxiliary motor 5 to enter the powergeneration power adjustment mode, so that the engine 1 operates in thepreset optimal economical area. In the power generation power adjustmentmode, the control module 101 may adjust the power generation power ofthe auxiliary motor 5 on the premise of enabling the engine 1 to operatein the preset optimal economical area. After the auxiliary motor 5enters the power generation power adjustment mode, the control module101 further adjusts the power generation power of the auxiliary motor 5according to the SOC value of the low-voltage storage battery 20.

Therefore, the engine 1 is enabled to operate in the preset optimaleconomical area, and because the engine 1 has lowest fuel consumptionand highest fuel economy in the preset optimal economical area, fuelconsumption of the engine 1 may be reduced, noise of the engine 1 may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor 5 has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel; and bycharging the low-voltage storage battery, power consumption requirementsof the low-voltage electric appliance device may be ensured, and whenthe auxiliary motor stops power generation and the power battery isfaulty or has an insufficient power level, low-voltage power supply ofthe entire vehicle may be implemented through the low-voltage storagebattery, and further it is ensured that the entire vehicle may travel inthe pure fuel mode, thereby improving travelling mileage of the entirevehicle.

Further, according to an embodiment of the present invention, thecontrol module 101 configured to: when the SOC value of the powerbattery 3 is greater than a preset limit value and is less than or equalto a first preset value, control, if the speed of the hybrid powerautomobile is less than a first preset speed, the auxiliary motor 5 toenter the power generation power adjustment mode.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery 3, for example, a value of determining tostop charging, and may be preferably 30%. The preset limit value may bea preset lower limit value of the SOC value of the power battery 3, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery 3 may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power battery 3is less than or equal to the preset limit value, the SOC value of thepower battery 3 falls within the first power level range. In this case,the power battery 3 performs only charging but does not performdischarging. When the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue, the SOC value of the power battery 3 falls within the secondpower level range. In this case, the power battery 3 has a chargingrequirement, that is, the power battery 3 may be actively charged. Whenthe SOC value of the power battery 3 is greater than the first presetvalue, the SOC value of the power battery 3 falls within the third powerlevel range. In this case, the power battery 3 may be not charged, thatis, the power battery 3 is not actively charged.

Specifically, after obtaining the SOC value of the power battery 3 andthe speed of the hybrid power automobile, the control module 101 maydetermine a range within which the SOC value of the power battery 3falls. If the SOC value of the power battery 3 falls within the secondpower level range, and the SOC value of the power battery 3 is greaterthan the preset limit value and is less than or equal to the firstpreset value, it indicates that the power battery 3 may be charged. Inthis case, the control module 101 further determines whether the speedof the hybrid power automobile is less than the first preset speed. Ifthe speed of the hybrid power automobile is less than the first presetspeed, the control module 101 controls the auxiliary motor 5 to enterthe power generation power adjustment mode. In this case, the speed ofthe hybrid power automobile is relatively low, a needed drive force isrelatively small, the power motor 2 is sufficient to drive the hybridpower automobile to travel, and the engine 1 may drive only theauxiliary motor 5 to perform power generation, but does not participatein drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is greater than the preset limit value andis less than or equal to the first preset value, and the speed of thehybrid power automobile is less than the first preset speed, obtain anentire vehicle requirement power of the hybrid power automobile; andwhen the entire vehicle requirement power is less than or equal to amaximum allowed power generation power of the auxiliary motor 5, controlthe auxiliary motor 5 to enter the power generation power adjustmentmode.

To be specific, after determining that the SOC value of the powerbattery 3 is greater than the preset limit value and is less than orequal to the first preset value, and the speed of the hybrid powerautomobile is less than the first preset speed, the control module 101may further determine whether the entire vehicle requirement power isgreater than the maximum allowed power generation power of the auxiliarymotor 5. If the entire vehicle requirement power is less than or equalto the maximum allowed power generation power of the auxiliary motor 5,the control module 101 controls the auxiliary motor 5 to enter the powergeneration power adjustment mode. In this case, a drive force needed bythe entire vehicle is relatively small, the entire vehicle requirementpower is relatively small, the power motor 2 is sufficient to drive thehybrid power automobile to travel, and the engine 1 may drive only theauxiliary motor 5 to perform power generation, but does not participatein drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, the control module 101 is further configured to: when theSOC value of the power battery is greater than the preset limit valueand is less than or equal to the first preset value, the speed of thehybrid power automobile is less than the first preset speed, and theentire vehicle requirement power is less than or equal to the maximumallowed power generation power of the auxiliary motor, obtain anaccelerator pedal depth of the hybrid power automobile and an entirevehicle resistance of the hybrid power automobile; and when theaccelerator pedal depth is less than or equal to a first preset depthand the entire vehicle resistance of the hybrid power automobile is lessthan or equal to a first preset resistance, control the auxiliary motorto enter the power generation power adjustment mode.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

To be specific, after determining that the SOC value of the powerbattery 3 is greater than the preset limit value and is less than orequal to the first preset value, the speed of the hybrid powerautomobile is less than the first preset speed, and the entire vehiclerequirement power is less than or equal to the maximum allowed powergeneration power of the auxiliary motor 5, the control module 101 mayfurther determine whether the accelerator pedal depth is greater thanthe first preset depth and whether the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance. Ifthe accelerator pedal depth is less than or equal to the first presetdepth or the entire vehicle resistance of the hybrid power automobile isless than or equal to the first preset resistance, the control module101 controls the auxiliary motor 5 to enter the power generation poweradjustment mode. In this case, a drive force needed by the entirevehicle is relatively small, the entire vehicle requirement power isrelatively small, the accelerator pedal depth is relatively small, theentire vehicle resistance is also relatively small, the power motor 2 issufficient to drive the hybrid power automobile to travel, and theengine 1 may drive only the auxiliary motor 5 to perform powergeneration, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

Additionally, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is less than the preset limit value, the speed of thehybrid power automobile is greater than or equal to the first presetspeed, the entire vehicle requirement power is greater than the maximumallowed power generation power of the auxiliary motor 5, the acceleratorpedal depth is greater than the first preset depth, or the entirevehicle resistance of the hybrid power automobile is greater than thefirst preset resistance, control the engine 1 to participate in drive.

To be specific, when the SOC value of the power battery 3 is less thanthe preset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor 5, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, thecontrol module 101 controls the engine 1 to participate in drive. Inthis case, the power battery 3 does not perform discharging again, theentire vehicle needs a relatively large drive force, the entire vehiclerequirement power is relatively large, the accelerator pedal depth isrelatively large or the entire vehicle resistance is also relativelylarge, the power motor 2 is insufficient to drive the hybrid powerautomobile to travel, and the engine 1 participates in drive to performsupplemental drive.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, the control module 101 is further configured to: whenthe entire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, control the engine 1 toparticipate in drive to enable the engine 1 to output power to wheelsthrough the clutch 6.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, control the engine 1 to participate in drive to enable the engine1 to output power to wheels through the clutch 6; when the SOC value ofthe power battery 3 is less than or equal to the first preset value, thespeed of the hybrid power automobile is less than the first preset speedand the accelerator pedal depth is greater than the first preset depth,control the engine 1 to participate in drive to enable the engine 1 tooutput power to the wheels through the clutch 6; and when the SOC valueof the power battery 3 is less than or equal to the first preset value,the speed of the hybrid power automobile is less than the first presetspeed and the entire vehicle resistance of the hybrid power automobileis greater than the first preset resistance, control the engine 1 toparticipate in drive to enable the engine 1 to output power to thewheels through the clutch 6.

To be specific, the control module 101 may obtain the SOC value of thepower battery 3, the accelerator pedal depth of the hybrid powerautomobile, the speed, the entire vehicle resistance and the entirevehicle requirement power in real time, and determine the SOC value ofthe power battery 3, the accelerator pedal depth of the hybrid powerautomobile, the speed and the entire vehicle resistance:

First, when the SOC value of the power battery 3 is less than the presetlimit value, because the power level of the power battery 3 isexcessively low, and the power battery 3 cannot provide sufficientelectric energy, the control module 101 controls the engine 1 and thepower motor 2 to simultaneously participate in drive. In this case, thecontrol module 101 may further control the engine 1 to drive theauxiliary motor 5 to perform power generation, and by adjusting thepower generation power of the auxiliary motor 5, the engine 1 is enabledto operate in the preset optimal economical area.

Second, when the SOC value of the power battery 3 is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed and the accelerator pedal depth isgreater than the first preset depth, because the accelerator pedal depthis relatively large, the control module 101 controls the engine 1 andthe power motor 2 to simultaneously participate in drive. In this case,the control module 101 may further control the engine 1 to drive theauxiliary motor 5 to perform power generation, and by adjusting thepower generation power of the auxiliary motor 5, the engine 1 is enabledto operate in the preset optimal economical area.

Third, when the SOC value of the power battery 3 is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed and the entire vehicle resistance ofthe hybrid power automobile is greater than the first preset resistance,because the entire vehicle resistance is relatively large, the controlmodule 101 controls the engine 1 and the power motor 2 to simultaneouslyparticipate in drive. In this case, the control module 101 may furthercontrol the engine 1 to drive the auxiliary motor 5 to perform powergeneration, and by adjusting the power generation power of the auxiliarymotor 5, the engine 1 is enabled to operate in the preset optimaleconomical area.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine 1 to participate in drive toenable the engine 1 to output power to the wheels 7 through the clutch6.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module 101 isfurther configured to: when the SOC value of the power battery 3 isgreater than the first preset value, control the engine 1 not to drivethe auxiliary motor 5 to perform power generation. In this case, thepower battery 3 has an approximately full power level, and does not needto be charged, and the engine 1 does not drive the auxiliary motor 5 toperform power generation. To be specific, when the power battery 3 hasan approximately full power level, the engine 1 does not drive theauxiliary motor 5 to perform power generation, and therefore theauxiliary motor 5 does not charge the power battery 3.

Further, after the auxiliary motor 5 enters the power generation poweradjustment mode, the control module 101 may adjust the power generationpower of the auxiliary motor 5. A process of adjusting the powergeneration power of the control module 101 of this embodiment of thepresent invention is specifically described below.

According to an embodiment of the present invention, the control module101 is further configured to: after the auxiliary motor 5 enters thepower generation power adjustment mode, adjust the power generationpower of the auxiliary motor 5 according to the entire vehiclerequirement power of the hybrid power automobile, the charging power ofthe power battery 3, the charging power of the low-voltage storagebattery 20, and the SOC value of the low-voltage storage battery 20.

Specifically, a formula of adjusting the power generation power of theauxiliary motor 5 according to the entire vehicle requirement power ofthe hybrid power automobile, the charging power of the power battery 3and the charging power of the low-voltage storage battery 20 may be asfollows:

P1=P2+P3+P4, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor 5, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery 3, P4 is the charging power of the low-voltage storage battery20, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices include the firstelectric appliance device 10 and the second electric appliance device30, that is, the electric appliance device power P21 may include powerneeded by the high-voltage electric appliance device and the low-voltageelectric appliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor 2, and the control module101 may obtain the entire vehicle drive power P11 according to a presetaccelerator-torsional moment curve of the power motor 2 and a rotationalspeed of the power motor 2, where the preset accelerator-torsionalmoment curve may be determined during power matching of the hybrid powerautomobile. The control module 101 may obtain the electric appliancedevice power P21 in real time according to electric appliance devicesrunning on the entire vehicle, for example, calculate the electricappliance device power P21 through DC consumption on a bus. The controlmodule 101 may obtain the charging power P3 of the power battery 3according to the SOC value of the power battery 3, and obtain thecharging power P4 of the low-voltage storage battery 20 according to theSOC value of the low-voltage storage battery 20.

Specifically, when the hybrid power automobile is travelling, thecontrol module 101 may obtain the charging power P3 of the power battery3, the charging power P4 of the low-voltage storage battery 20, theentire vehicle drive power P11 and the electric appliance device powerP21, and use a sum of the charging power P3 of the power battery 3, thecharging power P4 of the low-voltage storage battery 20, the entirevehicle drive power P11 and the electric appliance device power P21 asthe power generation power P1 of the auxiliary motor 5. Therefore, thecontrol module 101 may adjust the power generation power of theauxiliary motor 5 according to the calculated P1 value. For example, thecontrol module 101 may control the output torque and the rotationalspeed of the engine 1 according to the calculated P1 value, so as toadjust the power for the engine 1 to drive the auxiliary motor 5 toperform power generation.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: obtain an SOC value changerate of the power battery 3, and adjust the power generation power ofthe auxiliary motor 5 according to a relationship between the entirevehicle requirement power P2 and a minimum output power Pmincorresponding to the optimal economical area of the engine 1, the SOCvalue change rate of the power battery 3, the SOC value of thelow-voltage storage battery 20, and the SOC value change rate of thelow-voltage storage battery 20.

It should be understood that, the control module 101 may obtain the SOCvalue change rate of the power battery 3 according to the SOC value ofthe power battery 3, for example, collect the SOC value of the powerbattery 3 once at each time interval t. In this way, a ratio of adifference between a current SOC value and a former SOC value of thepower battery 3 to the time interval t may be used as the SOC valuechange rate of the power battery 3. Similarly, the control module 101may obtain the SOC value change rate of the low-voltage storage battery20 according to the SOC value of the low-voltage storage battery 20, forexample, collect the SOC value of the low-voltage storage battery 20once at each time interval t. In this way, a ratio of a differencebetween a current SOC value and a former SOC value of the low-voltagestorage battery 20 to the time interval t may be used as the SOC valuechange rate of the low-voltage storage battery 20.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After determining theminimum output power Pmin corresponding to the optimal economical areaof the engine, the control module 101 may adjust the power generationpower of the auxiliary motor 5 according to the relationship between theentire vehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine 1, the SOCvalue change rate of the power battery 3, the SOC value of thelow-voltage storage battery 20, and the SOC value change rate of thelow-voltage storage battery 20.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine 1 may perform only power generation but does not participatein drive, and because the engine does not participate in drive, theclutch does not need to be used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness, so as to maintain low-speed electric balance andlow-speed smoothness of the entire vehicle and improve performance ofthe entire vehicle.

A specific adjusting manner in which after the auxiliary motor 5 entersthe power generation power adjustment mode, the control module 101adjusts the power generation power of the auxiliary motor 5 according tothe relationship between the entire vehicle requirement power P2 and theminimum output power Pmin corresponding to the optimal economical areaof the engine 1, the SOC value change rate of the power battery 3, theSOC value of the low-voltage storage battery 20, and the SOC valuechange rate of the low-voltage storage battery 20 is further describedbelow.

Specifically, the control module 101 is further configured to: when theSOC value of the low-voltage storage battery 20 is greater than a presetlow power level threshold, obtain the charging power P3 of the powerbattery 3 according to the SOC value change rate of the power battery 3,and determine whether the charging power P3 of the power battery 3 isless than the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine 1 and theentire vehicle requirement power P2. If the charging power P3 of thepower battery 3 is less than the difference between the minimum outputpower Pmin corresponding to the optimal economical area of the engine 1and the entire vehicle requirement power P2, the control module 101controls the engine 1 to perform power generation at the minimum outputpower to adjust the power generation power of the auxiliary motor 5; orif the charging power P3 of the power battery 3 is greater than or equalto the difference between the minimum output power Pmin corresponding tothe optimal economical area of the engine 1 and the entire vehiclerequirement power P2, the control module 101 obtains the output power ofthe engine 1 in the preset optimal economical area according to the sumof the charging power P3 of the power battery 3 and the entire vehiclerequirement power P2, and controls the engine 1 to perform powergeneration at the obtained output power to adjust the power generationpower of the auxiliary motor 5.

Specifically, the control module 101 is further configured to: when theSOC value of the low-voltage storage battery 20 is less than or equal tothe preset low power level threshold, obtain the SOC value change rateof the low-voltage storage battery 20 and the SOC value change rate ofthe power battery 3, obtain the charging power P4 of the low-voltagestorage battery 20 according to the SOC value change rate of thelow-voltage storage battery 20, obtain the charging power P3 of thepower battery 3 according to the SOC value change rate of the powerbattery 3, and determine whether the sum of the charging power P4 of thelow-voltage storage battery 20 and the charging power P3 of the powerbattery 3 is less than the difference between the minimum output powerPmin corresponding to the optimal economical area of the engine 1 andthe entire vehicle requirement power P2. If the sum of the chargingpower P4 of the low-voltage storage battery 20 and the charging power P3of the power battery 3 is less than the difference between the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1 and the entire vehicle requirement power P2, the control module101 controls the engine 1 to perform power generation at the minimumoutput power Pmin to adjust the power generation power of the auxiliarymotor 5; or if the sum of the charging power P4 of the low-voltagestorage battery 20 and the charging power P3 of the power battery 3 isgreater than or equal to the difference between the minimum output powerPmin corresponding to the optimal economical area of the engine 1 andthe entire vehicle requirement power P2, the control module 101 obtainsthe output power of the engine 1 in the preset optimal economical areaaccording to the sum of the charging power P3 of the power battery 3,the charging power P4 of the low-voltage storage battery 20 and theentire vehicle requirement power P2, and controls the engine 1 toperform power generation at the obtained output power to adjust thepower generation power of the auxiliary motor 5.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery 3 and the charging power P3 ofthe power battery 3 may be pre-stored in the control module 101.Therefore, after obtaining an SOC value change rate of the power battery3, the control module 101 may obtain a corresponding charging power P3of the power battery 3 by performing matching on the first relationshiptable. For example, a first relationship table between the SOC valuechange rate of the power battery 3 and the charging power P3 of thepower battery 3 may be shown in Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power of the power B1 B2 B3 B4 B5 battery 3

It can be learned from Table 1 that, when an SOC value change rate ofthe power battery 3 is A1, a corresponding charging power P3 of thepower battery 3 that the control module 101 may obtain is B1; when anSOC value change rate of the power battery 3 is A2, a correspondingcharging power P3 of the power battery 3 that the control module 101 mayobtain is B2; when an SOC value change rate of the power battery 3 isA3, a corresponding charging power P3 of the power battery 3 that thecontrol module 101 may obtain is B3; when an SOC value change rate ofthe power battery 3 is A4, a corresponding charging power P3 of thepower battery 3 that the control module 101 may obtain is B4; and whenan SOC value change rate of the power battery 3 is A5, a correspondingcharging power P3 of the power battery 3 that the control module 101 mayobtain is B5.

Similarly, a second relationship table between the SOC value change rateof the low-voltage storage battery 20 and the charging power P4 of thelow-voltage storage battery 20 may be pre-stored in the control module101. Therefore, after obtaining an SOC value change rate of thelow-voltage storage battery 20, the control module 101 may obtain acorresponding charging power P4 of the low-voltage storage battery 20 byperforming matching on the second relationship table. For example, asecond relationship table between the SOC value change rate of thelow-voltage storage battery 20 and the charging power P4 of thelow-voltage storage battery 20 may be shown in Table 2.

TABLE 2 SOC value change rate of the A11 A12 A13 A14 A15 low-voltagestorage battery 20 Charging power of the B11 B12 B13 B14 B15 low-voltagestorage battery 20

It can be learned from Table 2 that, when an SOC value change rate ofthe low-voltage storage battery 20 is A11, a corresponding chargingpower P4 of the low-voltage storage battery 20 that the control module101 may obtain is B11; when an SOC value change rate of the low-voltagestorage battery 20 is A12, a corresponding charging power P4 of thelow-voltage storage battery 20 that the control module 101 may obtain isB12; when an SOC value change rate of the low-voltage storage battery 20is A13, a corresponding charging power P4 of the low-voltage storagebattery 20 that the control module 101 may obtain is B13; when an SOCvalue change rate of the low-voltage storage battery 20 is A14, acorresponding charging power P4 of the low-voltage storage battery 20that the control module 101 may obtain is B14; and when an SOC valuechange rate of the low-voltage storage battery 20 is A15, acorresponding charging power P4 of the low-voltage storage battery 20that the control module 101 may obtain is B15.

Specifically, after the auxiliary motor 5 enters the power generationpower adjustment mode, the control module 101 may obtain the SOC valueof the low-voltage storage battery 20, the SOC value of the powerbattery 3, and the entire vehicle requirement power P2 (the sum of theentire vehicle drive power P11 and the electric appliance device powerP21), and then determine whether the SOC value of the low-voltagestorage battery 20 is greater than the preset low power level threshold.

If the SOC value of the low-voltage storage battery 20 is greater thanthe preset low power level threshold, the control module 101 obtains theSOC value change rate of the power battery 3, and queries for thecharging power P3 of the power battery 3 corresponding to the SOC valuechange rate of the power battery 3, so as to select an appropriatecharging power P3 to enable the SOC value of the power battery 3 toincrease; and further determines whether the charging power P3 of thepower battery 3 is less than the difference between the minimum outputpower Pmin corresponding to the optimal economical area of the engine 1and the entire vehicle requirement power P2. If yes, that is,P3<Pmin−P2, the control module 101 controls the engine 1 to performpower generation at the minimum output power Pmin to adjust the powergeneration power of the auxiliary motor 5, that is, controls the engine1 to run at the minimum output power Pmin corresponding to the optimaleconomical area; or if not, that is, P3≥Pmin−P2, the control module 101obtains the output power of the engine 1 in the preset optimaleconomical area according to the sum of the charging power P3 of thepower battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to adjust the power generation power of the auxiliary motor 5. Tobe specific, the control module 101 searches for a corresponding outputpower in the preset optimal economical area of the engine 1, where theobtained output power may be the sum of the charging power P3 of thepower battery 3 and the entire vehicle requirement power P2, that is,(P2+P3 or P11+P21+P3), and in this case, may control the engine 1 toperform power generation at the obtained output power.

If the SOC value of the low-voltage storage battery 20 is less than orequal to the preset low power level threshold, the control module 101obtains the SOC value change rate of the power battery 3, and queriesfor the charging power P3 of the power battery 3 corresponding to theSOC value change rate of the power battery 3, so as to select anappropriate charging power P3 to enable the SOC value of the powerbattery 3 to increase; obtains the SOC value change rate of thelow-voltage storage battery 20, and queries for the charging power P4 ofthe low-voltage storage battery 20 corresponding to the SOC value changerate of the low-voltage storage battery 20, to select an appropriatecharging power P4 to enable the SOC value of the low-voltage storagebattery 20 to increase; and further determines whether the sum of thecharging power P4 of the low-voltage storage battery 20 and the chargingpower P3 of the power battery 3 is less than the difference between theminimum output power Pmin corresponding to the optimal economical areaof the engine 1 and the entire vehicle requirement power P2. If yes,that is, P3+P4<Pmin−P2, the control module 101 controls the engine 1 toperform power generation at the minimum output power Pmin to adjust thepower generation power of the auxiliary motor 5, that is, controls theengine 1 to run at the minimum output power Pmin corresponding to theoptimal economical area, and to charge the power battery 3 and thelow-voltage storage battery 20 at a power equal to the minimum outputpower Pmin corresponding to the optimal economical area minus the entirevehicle requirement power P2, that is, Pmin−P2; or if not, that is,P3+P4≥Pmin−P2, the control module 101 obtains the output power of theengine 1 in the preset optimal economical area according to the sum ofthe charging power P3 of the power battery 3, the charging power P4 ofthe low-voltage storage battery 20 and the entire vehicle requirementpower P2, and controls the engine 1 to perform power generation at theobtained output power to adjust the power generation power of theauxiliary motor 5. To be specific, the control module 101 searches for acorresponding power in the preset optimal economical area of the engine1, where the obtained output power is the sum of the charging power P3of the power battery 3, the charging power P4 of the low-voltage storagebattery 20 and the entire vehicle requirement power P2, that is,(P2+P3+P4 or P11+P21+P3+P4), and controls the engine 1 to perform powergeneration at the obtained output power.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

To sum up, according to the power system of a hybrid power automobileproposed in this embodiment of the present invention, the engine outputspower to the wheels of the hybrid power automobile through the clutch,the power motor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, andwhen performing power generation under driving of the engine, theauxiliary motor implements at least one of charging the power battery,supplying power to the power motor, and supplying power to the DC-DCconverter, and the control module obtains the SOC value of the powerbattery, the SOC value of the low-voltage storage battery and the speedof the hybrid power automobile, and controls, according to the SOC valueof the power battery and the speed of the hybrid power automobile, theauxiliary motor to enter the power generation power adjustment mode, sothat the engine runs in the preset optimal economical area. After theauxiliary motor enters the power generation power adjustment mode, thecontrol module is further configured to adjust the power generationpower of the auxiliary motor according to the SOC value of thelow-voltage storage battery. Therefore, the engine is enabled not toparticipate in drive at a low speed, and therefore the clutch is notused, thereby reducing abrasion or slip friction of the clutch, reducingan unsmooth feeling, and improving comfortableness; and at a low speed,the engine is enabled to operate in an economical area, to perform onlypower generation but does not perform drive, thereby reducing fuelconsumption, reducing noise of the engine, maintaining low-speedelectric balance and low-speed smoothness of the entire vehicle, andimproving performance of the entire vehicle.

Embodiment 5

In some embodiments of the present invention, the control module 101 isconfigured to obtain an SOC (state of charge, also referred to asremaining power level) value of the power battery 3, an SOC value of thelow-voltage storage battery 20 and a speed of the hybrid powerautomobile, control a power generation power of the auxiliary motor 5according to the SOC value of the power battery 3, the SOC value of thelow-voltage storage battery 20 and the speed of the hybrid powerautomobile, and obtaining a power generation power of the engine 1according to the power generation power of the auxiliary motor 5 tocontrol the engine 1 to run in a preset optimal economical area.

It should be noted that, the SOC value of the power battery 3 and theSOC value of the low-voltage storage battery 20 may be collected througha battery management system of the hybrid power automobile, andtherefore the battery management system sends the SOC value of the powerbattery 3 and the SOC value of the low-voltage storage battery 20 thatare collected to the control module 101, so that the control module 101obtains the SOC value of the power battery 3 and the SOC value of thelow-voltage storage battery 20.

It should be further noted that, the preset optimal economical area ofthe engine 1 may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine 1, a horizontalcoordinate indicates a rotational speed of the engine 1, and a curve ais a fuel economy curve of the engine 1. An area corresponding to thefuel economy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine 1 arelocated on an optimal fuel economy curve of the engine, the engine islocated in the optimal economical area. Therefore, in this embodiment ofthe present invention, the control module 101 may enable, by controllingthe rotational speed and the output torque of the engine 1 to fall onthe fuel economy curve of the engine, for example, the curve a, theengine 1 to run in the preset optimal economical area.

Specifically, when the hybrid power automobile is travelling, the engine1 may output power to the wheels 7 of the hybrid power automobilethrough the clutch 6, and the engine 1 may further drive the auxiliarymotor 5 to perform power generation. Therefore, the output power of theengine mainly includes two parts, one part is output to the auxiliarymotor 5, that is, the power generation power for driving the auxiliarymotor 5 to perform power generation, and the other part is output to thewheels 7, that is, the drive power for driving the wheels 7.

When the engine 1 drives the auxiliary motor 5 to perform powergeneration, the control module 101 may first obtain the SOC value of thepower battery 3, the SOC value of the low-voltage storage battery 20 andthe speed of the hybrid power automobile, then control the powergeneration power of the auxiliary motor 5 according to the SOC value ofthe power battery 3, the SOC value of the low-voltage storage battery 20and the speed of the hybrid power automobile, and further obtain thepower generation power of the engine 1 according to the power generationpower of the auxiliary motor 5, so as to control the engine 1 to run inthe preset optimal economical area. In other words, the control module101 may control the power generation power of the auxiliary motor 5 onthe premise of enabling the engine 1 to operate in the preset optimaleconomical area.

Therefore, the engine 1 is enabled to operate in the preset optimaleconomical area, and because the engine 1 has lowest fuel consumptionand highest fuel economy in the preset optimal economical area, fuelconsumption of the engine 1 may be reduced, noise of the engine 1 may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor 5 has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel; and bycharging the low-voltage storage battery, power consumption requirementsof the low-voltage electric appliance device may be ensured, and whenthe auxiliary motor stops power generation and the power battery isfaulty or has an insufficient power level, low-voltage power supply ofthe entire vehicle may be implemented through the low-voltage storagebattery, and further it is ensured that the entire vehicle may travel inthe pure fuel mode, thereby improving travelling mileage of the entirevehicle.

Further, according to an embodiment of the present invention, thecontrol module 101 configured to: when the SOC value of the powerbattery 3 is greater than a preset limit value and is less than or equalto a first preset value, control the power generation power of theauxiliary motor 5 if the speed of the hybrid power automobile is lessthan a first preset speed.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery 3, for example, a value of determining tostop charging, and may be preferably 30%. The preset limit value may bea preset lower limit value of the SOC value of the power battery 3, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery 3 may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power battery 3is less than or equal to the preset limit value, the SOC value of thepower battery 3 falls within the first power level range. In this case,the power battery 3 performs only charging but does not performdischarging. When the SOC value of the power battery 3 is greater thanthe preset limit value and is less than or equal to the first presetvalue, the SOC value of the power battery 3 falls within the secondpower level range. In this case, the power battery 3 has a chargingrequirement, that is, the power battery 3 may be actively charged. Whenthe SOC value of the power battery 3 is greater than the first presetvalue, the SOC value of the power battery 3 falls within the third powerlevel range. In this case, the power battery 3 may be not charged, thatis, the power battery 3 is not actively charged. Specifically, afterobtaining the SOC value of the power battery 3 and the speed of thehybrid power automobile, the control module 101 may determine a rangewithin which the SOC value of the power battery 3 falls. If the SOCvalue of the power battery 3 falls within the second power level range,and the SOC value of the power battery 3 is greater than the presetlimit value and is less than or equal to the first preset value, itindicates that the power battery 3 may be charged. In this case, thecontrol module 101 further determines whether the speed of the hybridpower automobile is less than the first preset speed. If the speed ofthe hybrid power automobile is less than the first preset speed, thecontrol module 101 controls the power generation power of the auxiliarymotor 5. In this case, the speed of the hybrid power automobile isrelatively low, a needed drive force is relatively small, the powermotor 2 is sufficient to drive the hybrid power automobile to travel,and the engine 1 may drive only the auxiliary motor 5 to perform powergeneration, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is greater than the preset limit value andis less than or equal to the first preset value, and the speed of thehybrid power automobile is less than the first preset speed, obtain anentire vehicle requirement power of the hybrid power automobile; andwhen the entire vehicle requirement power is less than or equal to amaximum allowed power generation power of the auxiliary motor 5, controlthe power generation power of the auxiliary motor 5.

To be specific, after determining that the SOC value of the powerbattery 3 is greater than the preset limit value and is less than orequal to the first preset value, and the speed of the hybrid powerautomobile is less than the first preset speed, the control module 101may further determine whether the entire vehicle requirement power isgreater than the maximum allowed power generation power of the auxiliarymotor 5. If the entire vehicle requirement power is less than or equalto the maximum allowed power generation power of the auxiliary motor 5,the control module 101 controls the power generation power of theauxiliary motor 5. In this case, a drive force needed by the entirevehicle is relatively small, the entire vehicle requirement power isrelatively small, the power motor 2 is sufficient to drive the hybridpower automobile to travel, and the engine 1 may drive only theauxiliary motor 5 to perform power generation, but does not participatein drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, the control module 101 is further configured to: when theSOC value of the power battery 3 is greater than the preset limit valueand is less than or equal to the first preset value, the speed of thehybrid power automobile is less than the first preset speed, and theentire vehicle requirement power is less than or equal to the maximumallowed power generation power of the auxiliary motor 5, obtain anaccelerator pedal depth of the hybrid power automobile and an entirevehicle resistance of the hybrid power automobile; and when theaccelerator pedal depth is less than or equal to a first preset depthand the entire vehicle resistance of the hybrid power automobile is lessthan or equal to a first preset resistance, control the power generationpower of the auxiliary motor 5.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

To be specific, after determining that the SOC value of the powerbattery 3 is greater than the preset limit value and is less than orequal to the first preset value, the speed of the hybrid powerautomobile is less than the first preset speed, and the entire vehiclerequirement power is less than or equal to the maximum allowed powergeneration power of the auxiliary motor 5, the control module 101 mayfurther determine whether the accelerator pedal depth is greater thanthe first preset depth or whether the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance. Ifthe accelerator pedal depth is less than or equal to the first presetdepth and the entire vehicle resistance of the hybrid power automobileis less than or equal to the first preset resistance, the control module101 controls the power generation power of the auxiliary motor 5. Inthis case, a drive force needed by the entire vehicle is relativelysmall, the entire vehicle requirement power is relatively small, theaccelerator pedal depth is relatively small, the entire vehicleresistance is also relatively small, the power motor 2 is sufficient todrive the hybrid power automobile to travel, and the engine 1 may driveonly the auxiliary motor 5 to perform power generation, but does notparticipate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

According to a specific embodiment of the present invention, the controlmodule 101 is further configured to: when controlling the engine 1 toindividually drive the auxiliary motor 5 to perform power generation andcontrolling the power motor 2 to output a drive force alone, obtain thepower generation power of the engine 1 according to the followingformula:

P0=P2/η/ζ

where P0 is the power generation power of the engine 1, P1 is the powergeneration power of the auxiliary motor 5, η is belt transmissionefficiency, and ζ is efficiency of the auxiliary motor 5.

To be specific, if the engine 1 may perform only power generation butdoes not participate in drive, the control module 101 may calculate thepower generation power P0 of the engine 1 according to the powergeneration power of the auxiliary motor 5, the belt transmissionefficiency η and the efficiency ζ of the auxiliary motor 5, and controlthe engine 1 to drive the auxiliary motor 5 at the obtained powergeneration power P0 to perform power generation, so as to control thepower generation power of the auxiliary motor 5.

Additionally, according to an embodiment of the present invention, thecontrol module 101 is further configured to: when the SOC value of thepower battery 3 is less than the preset limit value, the speed of thehybrid power automobile is greater than or equal to the first presetspeed, the entire vehicle requirement power is greater than the maximumallowed power generation power of the auxiliary motor 5, the acceleratorpedal depth is greater than the first preset depth, or the entirevehicle resistance of the hybrid power automobile is greater than thefirst preset resistance, control the engine 1 to participate in drive.

To be specific, when the SOC value of the power battery 3 is less thanthe preset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor 5, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, thecontrol module 101 controls the engine 1 to participate in drive. Inthis case, the power battery 3 does not perform discharging again, theentire vehicle needs a relatively large drive force, the entire vehiclerequirement power is relatively large, the accelerator pedal depth isrelatively large or the entire vehicle resistance is also relativelylarge, the power motor 2 is insufficient to drive the hybrid powerautomobile to travel, and the engine 1 participates in drive to performsupplemental drive.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, the control module 101 is further configured to: whenthe entire vehicle requirement power is greater than the maximum allowedpower generation power of the auxiliary motor 5, control the engine 1 toparticipate in drive to enable the engine 1 to output power to wheelsthrough the clutch.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, control the engine 1 to participate in drive to enable the engine1 to output power to wheels through the clutch 6; when the SOC value ofthe power battery 3 is less than or equal to the first preset value, thespeed of the hybrid power automobile is less than the first preset speedand the accelerator pedal depth is greater than the first preset depth,control the engine 1 to participate in drive to enable the engine 1 tooutput power to the wheels through the clutch 6; and when the SOC valueof the power battery 3 is less than or equal to the first preset value,the speed of the hybrid power automobile is less than the first presetspeed and the entire vehicle resistance of the hybrid power automobileis greater than the first preset resistance, control the engine 1 toparticipate in drive to enable the engine 1 to output power to thewheels through the clutch 6.

To be specific, the control module 101 may obtain the SOC value of thepower battery 3, the accelerator pedal depth of the hybrid powerautomobile, the speed, the entire vehicle resistance and the entirevehicle requirement power in real time, and determine the SOC value ofthe power battery 3, the accelerator pedal depth of the hybrid powerautomobile, the speed and the entire vehicle resistance:

First, when the SOC value of the power battery 3 is less than the presetlimit value, because the power level of the power battery 3 isexcessively low, and the power battery 3 cannot provide sufficientelectric energy, the control module 101 controls the engine 1 and thepower motor 2 to simultaneously participate in drive. In this case, thecontrol module 101 may further control the engine 1 to drive theauxiliary motor 5 to perform power generation, and by controlling thepower generation power of the engine 1, the engine 1 is enabled tooperate in the preset optimal economical area.

Second, when the SOC value of the power battery 3 is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed and the accelerator pedal depth isgreater than the first preset depth, because the accelerator pedal depthis relatively large, the control module 101 controls the engine 1 andthe power motor 2 to simultaneously participate in drive. In this case,the control module 101 may further control the engine 1 to drive theauxiliary motor 5 to perform power generation, and by controlling thepower generation power of the engine 1, the engine 1 is enabled tooperate in the preset optimal economical area.

Third, when the SOC value of the power battery 3 is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed and the entire vehicle resistance ofthe hybrid power automobile is greater than the first preset resistance,because the entire vehicle resistance is relatively large, the controlmodule 101 controls the engine 1 and the power motor 2 to simultaneouslyparticipate in drive. In this case, the control module 101 may furthercontrol the engine 1 to drive the auxiliary motor 5 to perform powergeneration, and by controlling the power generation power of the engine1, the engine 1 is enabled to operate in the preset optimal economicalarea.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module 101 is further configured to: when the SOCvalue of the power battery 3 is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine 1 to participate in drive toenable the engine 1 to output power to the wheels 7 through the clutch6.

Therefore, the engine 1 may participate in drive when the drive forceoutput by the power motor 2 is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module 101 isfurther configured to: when the SOC value of the power battery 3 isgreater than the first preset value, control the engine 1 not to drivethe auxiliary motor 5 to perform power generation. In this case, thepower battery 3 has an approximately full power level, and does not needto be charged, and the engine 1 does not drive the auxiliary motor 5 toperform power generation. To be specific, when the power battery 3 hasan approximately full power level, the engine 1 does not drive theauxiliary motor 5 to perform power generation, and therefore theauxiliary motor 5 does not charge the power battery 3.

Further, when the engine 1 drives only the auxiliary motor 5 to performpower generation but does not participate in drive, the control module101 may control the power generation power of the auxiliary motor 5. Aprocess of controlling the power generation power of the control module101 of this embodiment of the present invention is specificallydescribed below.

According to an embodiment of the present invention, the control module101 is further configured to: control the power generation power of theauxiliary motor 5 according to the entire vehicle requirement power ofthe hybrid power automobile, the charging power of the power battery 3and the charging power of the low-voltage storage battery 20.

Specifically, a formula of controlling the power generation power of theauxiliary motor 5 according to the entire vehicle requirement power ofthe hybrid power automobile, the charging power of the power battery 3and the charging power of the low-voltage storage battery 20 is asfollows:

P1=P2+P3+P4, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor 5, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery 3, P4 is the charging power of the low-voltage storage battery20, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices include the firstelectric appliance device 10 and the second electric appliance device30, that is, the electric appliance device power P21 may include powerneeded by the high-voltage electric appliance device and the low-voltageelectric appliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor 2, and the control module101 may obtain the entire vehicle drive power P11 according to a presetaccelerator-torsional moment curve of the power motor 2 and a rotationalspeed of the power motor 2, where the preset accelerator-torsionalmoment curve may be determined during power matching of the hybrid powerautomobile. The control module 101 may obtain the electric appliancedevice power P21 in real time according to electric appliance devicesrunning on the entire vehicle, for example, calculate the electricappliance device power P21 through DC consumption on a bus. The controlmodule 101 may obtain the charging power P3 of the power battery 3according to the SOC value of the power battery 3, and obtain thecharging power P4 of the low-voltage storage battery 20 according to theSOC value of the low-voltage storage battery 20.

Specifically, when the hybrid power automobile is travelling, thecontrol module 101 may obtain the charging power P3 of the power battery3, the charging power P4 of the low-voltage storage battery 20, theentire vehicle drive power P11 and the electric appliance device powerP21, and use a sum of the charging power P3 of the power battery 3, thecharging power P4 of the low-voltage storage battery 20, the entirevehicle drive power P11 and the electric appliance device power P21 asthe power generation power P1 of the auxiliary motor 5. Therefore, thecontrol module 101 may control the power generation power of theauxiliary motor 5 according to the calculated P1 value. For example, thecontrol module 101 may control the output torque and the rotationalspeed of the engine 1 according to the calculated P1 value, so as tocontrol the power for the engine 1 to drive the auxiliary motor 5 toperform power generation.

Further, according to an embodiment of the present invention, thecontrol module 101 is further configured to: obtain an SOC value changerate of the power battery 3, and control the power generation power ofthe auxiliary motor 5 according to a relationship between the entirevehicle requirement power P2 and a minimum output power Pmincorresponding to the optimal economical area of the engine 1, the SOCvalue change rate of the power battery 3, the SOC value of thelow-voltage storage battery 20, and the SOC value change rate of thelow-voltage storage battery 20.

It should be understood that, the control module 101 may obtain the SOCvalue change rate of the power battery 3 according to the SOC value ofthe power battery 3, for example, collect the SOC value of the powerbattery 3 once at each time interval t. In this way, a ratio of adifference between a current SOC value and a former SOC value of thepower battery 3 to the time interval t may be used as the SOC valuechange rate of the power battery 3. Similarly, the control module 101may obtain the SOC value change rate of the low-voltage storage battery20 according to the SOC value of the low-voltage storage battery 20, forexample, collect the SOC value of the low-voltage storage battery 20once at each time interval t. In this way, a ratio of a differencebetween a current SOC value and a former SOC value of the low-voltagestorage battery 20 to the time interval t may be used as the SOC valuechange rate of the low-voltage storage battery 20.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After determining theminimum output power Pmin corresponding to the optimal economical areaof the engine, the control module 101 may control the power generationpower of the auxiliary motor 5 according to the relationship between theentire vehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine 1, the SOCvalue change rate of the power battery 3, the SOC value of thelow-voltage storage battery 20, and the SOC value change rate of thelow-voltage storage battery 20.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine 1 may perform only power generation but does not participatein drive, and because the engine does not participate in drive, theclutch does not need to be used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness, so as to maintain low-speed electric balance andlow-speed smoothness of the entire vehicle and improve performance ofthe entire vehicle.

A specific control manner in which when the engine 1 drives only theauxiliary motor 5 to perform power generation but does not participatein drive, the control module 101 adjusts the power generation power ofthe auxiliary motor 5 according to the relationship between the entirevehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine 1, the SOCvalue change rate of the power battery 3, the SOC value of thelow-voltage storage battery 20, and the SOC value change rate of thelow-voltage storage battery 20 is further described below.

Specifically, the control module 101 is further configured to: when theSOC value of the low-voltage storage battery 20 is greater than a presetlow power level threshold, obtain the charging power P3 of the powerbattery 3 according to the SOC value change rate of the power battery 3,and determine whether the charging power P3 of the power battery 3 isless than the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine 1 and theentire vehicle requirement power P2. If the charging power P3 of thepower battery 3 is less than the difference between the minimum outputpower Pmin corresponding to the optimal economical area of the engine 1and the entire vehicle requirement power P2, the control module 101controls the engine 1 to perform power generation at the minimum outputpower to control the power generation power of the auxiliary motor 5; orif the charging power of the power battery 3 is greater than or equal tothe difference between the minimum output power Pmin corresponding tothe optimal economical area of the engine 1 and the entire vehiclerequirement power P2, the control module 101 obtains the output power ofthe engine 1 in the preset optimal economical area according to the sumof the charging power P3 of the power battery 3 and the entire vehiclerequirement power P2, and controls the engine 1 to perform powergeneration at the obtained output power to control the power generationpower of the auxiliary motor 5.

Specifically, the control module 101 is further configured to: when theSOC value of the low-voltage storage battery 20 is less than or equal tothe preset low power level threshold, obtain the SOC value change rateof the low-voltage storage battery 20 and the SOC value change rate ofthe power battery 3, obtain the charging power P4 of the low-voltagestorage battery 20 according to the SOC value change rate of thelow-voltage storage battery 20, obtain the charging power P3 of thepower battery 3 according to the SOC value change rate of the powerbattery 3, and determine whether the sum of the charging power P4 of thelow-voltage storage battery 20 and the charging power P3 of the powerbattery 3 is less than the difference between the minimum output powerPmin corresponding to the optimal economical area of the engine 1 andthe entire vehicle requirement power P2. If the sum of the chargingpower P4 of the low-voltage storage battery 20 and the charging power P3of the power battery 3 is less than the difference between the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1 and the entire vehicle requirement power P2, the control module101 controls the engine 1 to perform power generation at the minimumoutput power Pmin to control the power generation power of the auxiliarymotor 5; or if the sum of the charging power P4 of the low-voltagestorage battery 20 and the charging power P3 of the power battery 3 isgreater than or equal to the difference between the minimum output powerPmin corresponding to the optimal economical area of the engine 1 andthe entire vehicle requirement power P2, the control module 101 obtainsthe output power of the engine 1 in the preset optimal economical areaaccording to the sum of the charging power P3 of the power battery 3,the charging power P4 of the low-voltage storage battery 20 and theentire vehicle requirement power P2, and controls the engine 1 toperform power generation at the obtained output power to control thepower generation power of the auxiliary motor 5.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery 3 and the charging power P3 ofthe power battery 3 may be pre-stored in the control module 101.Therefore, after obtaining an SOC value change rate of the power battery3, the control module 101 may obtain a corresponding charging power P3of the power battery 3 by performing matching on the first relationshiptable. For example, a first relationship table between the SOC valuechange rate of the power battery 3 and the charging power P3 of thepower battery 3 may be shown in Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power of the power B1 B2 B3 B4 B5 battery 3

It can be learned from Table 1 that, when an SOC value change rate ofthe power battery 3 is A1, a corresponding charging power P3 of thepower battery 3 that the control module 101 may obtain is B1; when anSOC value change rate of the power battery 3 is A2, a correspondingcharging power P3 of the power battery 3 that the control module 101 mayobtain is B2; when an SOC value change rate of the power battery 3 isA3, a corresponding charging power P3 of the power battery 3 that thecontrol module 101 may obtain is B3; when an SOC value change rate ofthe power battery 3 is A4, a corresponding charging power P3 of thepower battery 3 that the control module 101 may obtain is B4; and whenan SOC value change rate of the power battery 3 is A5, a correspondingcharging power P3 of the power battery 3 that the control module 101 mayobtain is B5.

Similarly, a second relationship table between the SOC value change rateof the low-voltage storage battery 20 and the charging power P4 of thelow-voltage storage battery 20 may be pre-stored in the control module101. Therefore, after obtaining an SOC value change rate of thelow-voltage storage battery 20, the control module 101 may obtain acorresponding charging power P4 of the low-voltage storage battery 20 byperforming matching on the second relationship table. For example, asecond relationship table between the SOC value change rate of thelow-voltage storage battery 20 and the charging power P4 of thelow-voltage storage battery 20 may be shown in Table 2.

TABLE 2 SOC value change rate of the A11 A12 A13 A14 A15 low-voltagestorage battery 20 Charging power of the B11 B12 B13 B14 B15 low-voltagestorage battery 20

It can be learned from Table 2 that, when an SOC value change rate ofthe low-voltage storage battery 20 is A11, a corresponding chargingpower P4 of the low-voltage storage battery 20 that the control module101 may obtain is B11; when an SOC value change rate of the low-voltagestorage battery 20 is A12, a corresponding charging power P4 of thelow-voltage storage battery 20 that the control module 101 may obtain isB12; when an SOC value change rate of the low-voltage storage battery 20is A13, a corresponding charging power P4 of the low-voltage storagebattery 20 that the control module 101 may obtain is B13; when an SOCvalue change rate of the low-voltage storage battery 20 is A14, acorresponding charging power P4 of the low-voltage storage battery 20that the control module 101 may obtain is B14; and when an SOC valuechange rate of the low-voltage storage battery 20 is A15, acorresponding charging power P4 of the low-voltage storage battery 20that the control module 101 may obtain is B15.

Specifically, when controlling the power generation power of theauxiliary motor 5, the control module 101 may obtain the SOC value ofthe low-voltage storage battery 20, the SOC value of the power battery3, and the entire vehicle requirement power P2 (the sum of the entirevehicle drive power P11 and the electric appliance device power P21),and then determine whether the SOC value of the low-voltage storagebattery 20 is greater than the preset low power level threshold.

If the SOC value of the low-voltage storage battery 20 is greater thanthe preset low power level threshold, the control module 101 obtains theSOC value change rate of the power battery 3, and queries for thecharging power P3 of the power battery 3 corresponding to the SOC valuechange rate of the power battery 3, so as to select an appropriatecharging power P3 to enable the SOC value of the power battery 3 toincrease; and further determines whether the charging power P3 of thepower battery 3 is less than the difference between the minimum outputpower Pmin corresponding to the optimal economical area of the engine 1and the entire vehicle requirement power P2. If yes, that is,P3<Pmin−P2, the control module 101 controls the engine 1 to performpower generation at the minimum output power Pmin to control the powergeneration power of the auxiliary motor 5, that is, controls the engine1 to run at the minimum output power Pmin corresponding to the optimaleconomical area; or if not, that is, P3≥Pmin−P2, the control module 101obtains the output power of the engine 1 in the preset optimaleconomical area according to the sum of the charging power P3 of thepower battery 3 and the entire vehicle requirement power P2, andcontrols the engine 1 to perform power generation at the obtained outputpower to control the power generation power of the auxiliary motor 5. Tobe specific, the control module 101 searches for a corresponding outputpower in the preset optimal economical area of the engine 1, where theobtained output power may be the sum of the charging power P3 of thepower battery 3 and the entire vehicle requirement power P2, that is,(P2+P3 or P11+P21+P3), and in this case, may control the engine 1 toperform power generation at the obtained output power.

If the SOC value of the low-voltage storage battery 20 is less than orequal to the preset low power level threshold, the control module 101obtains the SOC value change rate of the power battery 3, and queriesfor the charging power P3 of the power battery 3 corresponding to theSOC value change rate of the power battery 3, so as to select anappropriate charging power P3 to enable the SOC value of the powerbattery 3 to increase; obtains the SOC value change rate of thelow-voltage storage battery 20, and queries for the charging power P4 ofthe low-voltage storage battery 20 corresponding to the SOC value changerate of the low-voltage storage battery 20, to select an appropriatecharging power P4 to enable the SOC value of the low-voltage storagebattery 20 to increase; and further determines whether the sum of thecharging power P4 of the low-voltage storage battery 20 and the chargingpower P3 of the power battery 3 is less than the difference between theminimum output power Pmin corresponding to the optimal economical areaof the engine 1 and the entire vehicle requirement power P2. If yes,that is, P3+P4<Pmin−P2, the control module 101 controls the engine 1 toperform power generation at the minimum output power Pmin to control thepower generation power of the auxiliary motor 5, that is, controls theengine 1 to run at the minimum output power Pmin corresponding to theoptimal economical area, and to charge the power battery 3 and thelow-voltage storage battery 20 at a power equal to the minimum outputpower Pmin corresponding to the optimal economical area minus the entirevehicle requirement power P2, that is, Pmin−P2; or if not, that is,P3+P4≥Pmin−P2, the control module 101 obtains the power of the engine 1in the preset optimal economical area according to the sum of thecharging power P3 of the power battery 3, the charging power P4 of thelow-voltage storage battery 20 and the entire vehicle requirement powerP2, and controls the engine 1 to perform power generation at theobtained output power to control the power generation power of theauxiliary motor 5. To be specific, the control module 101 searches for acorresponding power in the preset optimal economical area of the engine1, where the obtained output power may be the sum of the charging powerP3 of the power battery 3, the charging power P4 of the low-voltagestorage battery 20 and the entire vehicle requirement power P2, that is,(P2+P3+P4 or P11+P21+P3+P4), and controls the engine 1 to perform powergeneration at the obtained output power.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

To sum up, according to the power system of a hybrid power automobileproposed in this embodiment of the present invention, the engine outputspower to the wheels of the hybrid power automobile through the clutch,the power motor outputs a drive force to the wheels of the hybrid powerautomobile, the power battery supplies power to the power motor, andwhen performing power generation under driving of the engine, theauxiliary motor implements at least one of charging the power battery,supplying power to the power motor, and supplying power to the DC-DCconverter, and the control module obtains the SOC value of the powerbattery, the SOC value of the low-voltage storage battery and the speedof the hybrid power automobile, controls the power generation power ofthe auxiliary motor according to the SOC value of the power battery, theSOC value of the low-voltage storage battery and the speed of the hybridpower automobile, and obtains the power generation power of the engineaccording to the power generation power of the auxiliary motor tocontrol the engine to run in the preset optimal economical area.Therefore, the engine is enabled not to participate in drive at a lowspeed, and therefore the clutch is not used, thereby reducing abrasionor slip friction of the clutch, reducing an unsmooth feeling, andimproving comfortableness; and at a low speed, the engine is enabled tooperate in an economical area, to perform only power generation but doesnot perform drive, thereby reducing fuel consumption, reducing noise ofthe engine, maintaining low-speed electric balance and low-speedsmoothness of the entire vehicle, and improving performance of theentire vehicle.

Moreover, an embodiment of the present invention further proposes arectification voltage stabilization circuit for power generation of amotor in a power system of a hybrid power automobile. The rectificationvoltage stabilization circuit for power generation of a motor in a powersystem of a hybrid power automobile of this embodiment of the presentinvention is described below with reference to accompanying drawings.

FIG. 8 is a structural block diagram of a power system of a hybrid powerautomobile according to an embodiment of the present invention. As shownin FIG. 8, the power system of a hybrid power automobile includes: anengine 1, a power motor 2, a power battery 3, a DC-DC converter 4, anauxiliary motor 5, and a voltage stabilization circuit 300.

As shown in FIG. 8 to FIG. 10, the engine 1 outputs power to wheels 7 ofthe hybrid power automobile through a clutch 6; and the power motor 2 isconfigured to output a drive force to the wheels 7 of the hybrid powerautomobile. To be specific, the power system of this embodiment of thepresent invention may provide power for normal travelling of the hybridpower automobile through the engine 1 and/or the power motor 2. In otherwords, in some embodiments of the present invention, power sources ofthe power system may be the engine 1 and the power motor 2, and eitherof the engine 1 and the power motor 2 may individually output power tothe wheels 7, or the engine 1 and the power motor 2 may simultaneouslyoutput power to the wheels 7.

The power battery 3 is configured to supply power to the power motor 2.The auxiliary motor 5 is connected to the engine 1. For example, theauxiliary motor 5 may be connected to the engine 1 through a wheel trainside of the engine 1, and the auxiliary motor 5 is connected to thepower motor 2, the DC-DC converter 4 and the power battery 3. Thevoltage stabilization circuit 300 is connected to between the auxiliarymotor 5 and the DC-DC converter 4, and the voltage stabilization circuit300 performs voltage stabilization processing on a direct current thatis output to the DC-DC converter 4 when the auxiliary motor 5 performspower generation, so that a stabilized voltage supplies power to alow-voltage electric appliance of the entire vehicle through the DC-DCconverter 4. In other words, after electric energy that is output whenthe auxiliary motor 5 performs power generation passes through thevoltage stabilization circuit 300, a stabilized voltage is output andsupplied to the DC-DC converter 4.

Therefore, the power motor 2 and the auxiliary motor 5 may respectivelyserve as a drive motor and a generator correspondingly, so that theauxiliary motor 5 may have relatively high power generation power andpower generation efficiency at a low speed, thereby satisfying powerconsumption requirements of low-speed travelling, maintaining low-speedelectric balance of the entire vehicle, maintaining low-speedsmoothness, and improving performance of the entire vehicle. Moreover,voltage stabilization processing may be performed, through the voltagestabilization circuit 300, on the direct current that is output to theDC-DC converter 4 when the auxiliary motor 5 performs power generation,so that an input voltage of the DC-DC converter 4 is kept stable,thereby ensuring normal operating of the DC-DC converter.

Further, when performing power generation under driving of the engine 1,the auxiliary motor 5 may implement at least one of charging the powerbattery 3, supplying power to the power motor 2, and supplying power tothe DC-DC converter 4. In other words, the engine 1 may drive theauxiliary motor 5 to perform power generation, and electric energygenerated by the auxiliary motor 5 may be provided to at least one ofthe power battery 3, the power motor 2, and the DC-DC converter 4. Itshould be understood that, the engine 1 may drive, while outputtingpower to the wheels 7, the auxiliary motor 5 to perform powergeneration, or may individually drive the auxiliary motor 5 to performpower generation.

The auxiliary motor 5 may be a BSG motor. It should be noted that, theauxiliary motor 5 belongs to a high-voltage motor. For example, a powergeneration voltage of the auxiliary motor 5 is equivalent to a voltageof the power battery 3, and therefore electric energy generated by theauxiliary motor 5 may directly charge the power battery 3 withoutvoltage conversion, and may further supply power to the power motor 2and/or the DC-DC converter 4. Moreover, the auxiliary motor 5 may alsobelong to an efficient generator. For example, power generationefficiency above 97% may be achieved provided that the auxiliary motor 5is driven at an idling rotational speed of the engine 1 to perform powergeneration.

It should be noted that, the voltage stabilization circuit 300 may bedisposed on an output line of the auxiliary motor 5, and the auxiliarymotor 5 is connected to the power motor 2, the power battery 3 and theDC-DC converter 4 through the voltage stabilization circuit 300, asshown in FIG. 9b and FIG. 9c . In this case, when performing powergeneration, the auxiliary motor 5 may output a stabilized voltagethrough the voltage stabilization circuit 300, to charge the powerbattery 3 at the stabilized voltage, supply power to the power motor 2at the stabilized voltage, and supply power to the DC-DC converter 4 atthe stabilized voltage. Therefore, regardless of whether the powerbattery 3 is connected to the DC-DC converter 4, normal operating of theDC-DC converter 4 can be ensured. The voltage stabilization circuit 300may alternatively be disposed on an incoming line of the DC-DC converter4, the auxiliary motor 5 may be connected to the DC-DC converter 4 andthe power battery 3, and furthermore the power battery 3 may beconnected to the DC-DC converter 4, as shown in FIG. 8 and FIG. 9a .Therefore, when the power battery 3 is disconnected from the DC-DCconverter 4, the voltage that is output to the DC-DC converter 4 whenthe auxiliary motor 5 performs power generation is still stable, therebyensuring normal operating of the DC-DC converter 4.

Further, the auxiliary motor 5 may be configured to start the engine 1,that is, the auxiliary motor 5 may implement a function of starting theengine 1. For example, when starting the engine 1, the auxiliary motor 5may drive a crank shaft of the engine 1 to rotate, so that a piston ofthe engine 1 reaches an ignition location, thereby starting the engine1. Therefore, the auxiliary motor 5 may implement a function of astarter in a related technology.

As described above, both the engine 1 and the power motor 2 may beconfigured to drive the wheels 7 of the hybrid power automobile. Forexample, as shown in FIG. 9a and FIG. 9b , the engine 1 and the powermotor 2 jointly drive same wheels of the hybrid power automobile, forexample, a pair of front wheels 7 (including a left front wheel and aright front wheel). For another example, as shown in FIG. 9c , theengine 1 may drive first wheels of the hybrid power automobile, forexample, a pair of front wheels 71 (including a left front wheel and aright front wheel), and the power motor 2 may drive second wheels of thehybrid power automobile, for example, a pair of rear wheels 72(including a left rear wheel and a right rear wheel).

In other words, when the engine 1 and the power motor 2 jointly drivethe pair of front wheels 71, a drive force of the power system is outputto the pair of front wheels 71, and the entire vehicle uses a drivemanner of two-wheel drive; or when the engine 1 drives the pair of frontwheels 71 and the power motor 2 drives the pair of rear wheels 72, adrive force of the power system is output to the pair of front wheels 71and the pair of rear wheels 72, and the entire vehicle uses a drivemanner of four-wheel drive.

Further, in the two-wheel drive manner, with reference to FIG. 9a andFIG. 9b , the power system of a hybrid power automobile further includesa differential 8, a main reducer 9, and a transmission 90, where theengine 1 outputs power to the first wheels of the hybrid powerautomobile, for example, the pair of front wheels 71 through the clutch6, the transmission 90, the main reducer 9, and the differential 8, andthe power motor 2 outputs a drive force to the first wheels of thehybrid power automobile, for example, the pair of front wheels 71through the main reducer 9 and the differential 8. The clutch 6 and thetransmission 90 may be integrated.

In the four-wheel drive manner, with reference to FIG. 9c , the powersystem of a hybrid power automobile further includes a firsttransmission 91 and a second transmission 92, where the engine 1 outputspower to the first wheels of the hybrid power automobile, for example,the pair of front wheels 71 through the clutch 6 and the firsttransmission 91, and the power motor 2 outputs a drive force to thesecond wheels of the hybrid power automobile, for example, the pair ofrear wheels 72 through the second transmission 92.

The clutch 6 and the first transmission 91 may be integrated.

In an embodiment of the present invention, because the power generationvoltage of the auxiliary motor 5 is usually connected between two endsof the power battery 3, when the power battery 3 is connected to theDC-DC converter 4, the voltage that is input to the DC-DC converter 4 isstable. When the power battery 3 is invalid or damaged and isdisconnected from the DC-DC converter 4, the alternating current that isoutput when the auxiliary motor 5 performs power generation needs to becontrolled, that is, voltage stabilization processing may be performed,through the voltage stabilization circuit 300, on the direct currentthat is output to the DC-DC converter 4 when the auxiliary motor 5performs power generation.

In some embodiments of the present invention, as shown in FIG. 10, theauxiliary motor 5 includes an auxiliary-motor controller 51, theauxiliary-motor controller 51 includes an inverter 511 and an adjuster512, and the adjuster 512 is configured to: when the power battery 3 isdisconnected from the DC-DC converter 4, output a first adjustmentsignal and a second adjustment signal according to an output signal ofthe voltage stabilization circuit 300, so that a direct-current bus-barvoltage output by the inverter 511 is kept stable, where the firstadjustment signal is used to adjust a d-axis current of the auxiliarymotor 5, and the second adjustment signal is used to adjust a q-axiscurrent of the auxiliary motor 5.

Further, in some embodiments, as shown in FIG. 10, the voltagestabilization circuit 300 includes a first voltage sampler 61 and atarget voltage collector 62. The first voltage sampler 61 performssampling on the direct-current bus-bar voltage output by the inverter511 to obtain a first voltage sampling value, and outputs the firstvoltage sampling value to the adjuster 512, and the target voltagecollector 62 obtains a target reference voltage, and sends the targetreference voltage to the adjuster 512. The adjuster 512 is configured tooutput the first adjustment signal and the second adjustment signalaccording to a voltage difference between the target reference voltageand the first voltage sampling value. The output signal of the voltagestabilization circuit 300 includes the first voltage sampling value andthe target reference voltage.

Specifically, the auxiliary-motor controller 51 is connected to theDC-DC converter 4 through the voltage stabilization circuit 300. Theauxiliary-motor controller 51 outputs the direct-current bus-bar voltagethrough the inverter 511, and the first voltage sampler 61 performssampling on the direct-current bus-bar voltage output by the inverter511 to obtain the first voltage sampling value, and outputs the firstvoltage sampling value to the adjuster 512. The target voltage collector62 obtains the target reference voltage, and sends the target referencevoltage to the adjuster 512, and the adjuster 512 outputs the firstadjustment signal and the second adjustment signal according to thevoltage difference between the target reference voltage and the firstvoltage sampling value. The d-axis current of the auxiliary motor 5 isadjusted through the first adjustment signal, and the q-axis current ofthe auxiliary motor 5 is adjusted through the second adjustment signal,so that when the power battery 3 is disconnected from the DC-DCconverter 4, the auxiliary-motor controller 51 controls the inverter 511according to the d-axis current and the q-axis current of the auxiliarymotor 5, and therefore the direct-current bus-bar voltage output by theinverter 511 is kept stable.

In some examples, the inverter 511 may be controlled by using a PWM(pulse width modulation) technology, so that the direct-current bus-barvoltage output by the inverter 511 is kept stable. As shown in FIG. 11,the adjuster 512 includes an error calculation unit a, a first PIDadjustment unit b, and a second PID adjustment unit c.

The error calculation unit a is connected to the first voltage sampler61 and the target voltage collector 62, and the error calculation unit ais configured to obtain the voltage difference between the targetreference voltage and the first voltage sampling value. The first PIDadjustment unit b is connected to the error calculation unit a, and thefirst PID adjustment unit b adjusts the voltage difference between thetarget reference voltage and the first voltage sampling value to outputthe first adjustment signal. The second PID adjustment unit c isconnected to the error calculation unit a, and the second PID adjustmentunit c adjusts the voltage difference between the target referencevoltage and the first voltage sampling value to output the secondadjustment signal.

Specifically, as shown in FIG. 11, the first voltage sampler 61performs, in real time, sampling on the direct-current bus-bar voltageoutput by the inverter 511 to obtain a first voltage sampling value, andoutputs the first voltage sampling value to the error calculation unita, and the target voltage collector 62 obtains a target referencevoltage, and outputs the target reference voltage to the errorcalculation unit a. The error calculation unit a obtains the voltagedifference between the target reference voltage and the first voltagesampling value, and inputs the difference to the first PID adjustmentunit b and the second PID adjustment unit c, to output the firstadjustment signal (that is, Id* in FIG. 11) through the first PIDadjustment unit b and output the second adjustment signal (that is, Iq*in FIG. 11) through the second PID adjustment unit c. In this case, athree-phase current output by the auxiliary motor 5 is converted into ad-axis current Id and a q-axis current Iq in a dq coordinate systemthrough 3S/2R conversion, a difference between Id* and Id and adifference between Iq* and Iq are respectively obtained, and thedifferences are respectively controlled through corresponding PIDadjusters to obtain an α-axis voltage Uα of the auxiliary motor 5 and aβ-axis voltage Uβ of the auxiliary motor 5. Uα and Uβ are input to anSVPWM module, to output a three-phase duty cycle, the inverter 511 iscontrolled through the duty cycle, and the d-axis current Id and theq-axis current Iq output by the auxiliary motor 5 are adjusted throughthe inverter 511; and then the adjusted d-axis current of the auxiliarymotor is adjusted again through the first adjustment signal, and theq-axis current of the auxiliary motor is adjusted again through thesecond adjustment signal. Therefore, closed-loop control is formed onthe d-axis current and the q-axis current of the auxiliary motor.Through the closed-loop control, the direct-current bus-bar voltageoutput by the inverter 511 can be kept stable, that is, thedirect-current voltage output to the DC-DC converter 4 when theauxiliary motor 5 performs power generation is kept stable.

It should be noted that, the direct-current voltage output by theinverter 511 in the auxiliary-motor controller 51 and a counterelectromotive force output by the auxiliary motor 5 have a particularcorrelation. To ensure control efficiency, the voltage output by theinverter 511 may be set to 3/2 of a phase voltage (that is, a maximumphase voltage in a drive state is ⅔ of the direct-current bus-barvoltage). Therefore, the direct-current voltage output by the inverter511 and the rotational speed of the auxiliary motor 5 have a particularrelationship. When the rotational speed of the auxiliary motor 5 ishigher, the direct-current voltage output by the inverter 511 is higher;and when the rotational speed of the auxiliary motor 5 is lower, thedirect-current voltage output by the inverter 511 is lower.

Further, to ensure that the direct-current voltage input to the DC-DCconverter 4 falls within a preset voltage range, in some embodiments ofthe present invention, as shown in FIG. 10, the voltage stabilizationcircuit 300 may further include a voltage stabilizer 63, a secondvoltage sampler 64 and a voltage stabilization controller 65.

The voltage stabilizer 63 is connected to a direct-current output end ofthe inverter 511, the voltage stabilizer 63 performs voltagestabilization processing on the direct-current bus-bar voltage output bythe inverter 511, and an output end of the voltage stabilizer 63 isconnected to an input end of the DC-DC converter 4. The second voltagesampler 64 performs sampling on an output voltage of the voltagestabilizer 63 to obtain a second voltage sampling value. The voltagestabilization controller 65 is connected to the voltage stabilizer 63and the second voltage sampler 64, and the voltage stabilizationcontroller 65 is configured to control the output voltage of the voltagestabilizer 63 according to a preset reference voltage and the secondvoltage sampling value to enable the output voltage of the voltagestabilizer 63 to fall within the preset voltage range.

In some examples, a switch-type voltage stabilization circuit, forexample, a boost circuit may be used as the voltage stabilizer 63, andnot only can perform boost, but also has high control precision. Asilicon carbide MOSFET, for example, IMW120R45M1 of Infineon may be useda switch device in the boost circuit, may withstand a voltage of 1200 V,has an internal resistance of 45 mΩ, is characterized by a highwithstood voltage, a small internal resistance, and good heat-conductingperformance, and has a loss dozens of times smaller than that of ahigh-speed IGBT of a same specification. 1EDI60N12AF of Infineon may beused as a drive chip of the voltage stabilizer 63, where core-lessvoltage transformation and isolation is used, and control is safe andreliable. It may be understood that, the drive chip may generate a drivesignal.

In some other examples, a buck-boost circuit may be used as the voltagestabilizer 63, can perform buck when the rotational speed of the motoris high and perform boost when the rotational speed of the motor is low,and has high control precision.

In still some other examples, a linear voltage stabilization circuit ora three-terminal voltage stabilization circuit (for example, LM317 and7805) may be further used as the voltage stabilizer 63.

It may be understood that, for ease of circuit design, the first voltagesampler 61 and the second voltage sampler 64 may have a same circuitstructure. For example, the first voltage sampler 61 and the secondvoltage sampler 64 may each include a differential voltage circuit thatis characterized by high precision and convenient adjustment of amagnification factor.

Optionally, a PWM dedicated modulation chip SG3525 may be used as thevoltage stabilization controller 65, and is characterized by a smallvolume, simple control, and a stable PWM wave that can be output.

For example, an operating process of the foregoing power system of ahybrid power automobile is: The second voltage sampler 64 performssampling on the output voltage of the voltage stabilizer 63 to obtainthe second voltage sampling value, and outputs the second voltagesampling value to the chip SG3525, and the chip SG3525 may set thereference voltage, and compare the reference voltage with the secondvoltage sampling value; and then may generate two paths of PWM waveswith reference to a triangular wave generated by the chip SG3525, andcontrol the voltage stabilizer 63 through the two paths of PWM waves toenable the voltage output by the voltage stabilizer 63 to the DC-DCconverter 4 to fall within the preset voltage range, for example, 11 Vto 13 V. Therefore, normal operating of low-voltage load in the hybridpower automobile can be ensured.

It should be noted that, if the output direct-current bus-bar voltage isexcessively low, and the second voltage sampling value is quite small,SG3525 may send a PWM wave whose duty cycle is relatively large, toperform boost.

Therefore, the auxiliary motor 5 and the DC-DC converter 4 have oneindividual voltage stabilization power supply channel, and when thepower battery 3 is faulty, and is disconnected from the DC-DC converter4, the individual voltage stabilization power supply channel of theauxiliary motor 5 and the DC-DC converter 4 may ensure low-voltage powerconsumption of the entire vehicle, to ensure that the entire vehicle mayimplement travelling in the pure fuel mode, and improve travellingmileage of the entire vehicle.

In a specific of the present invention, as shown in FIG. 12, when thepower battery 3 is damaged and is disconnected from the DC-DC converter4, the voltage stabilization circuit 300 is connected to an incomingline end of the DC-DC converter 4.

The power motor 2 further includes a second controller 21, and theauxiliary-motor controller 51 is connected to the second controller 21and connected to the DC-DC converter 4 through the voltage stabilizationcircuit 300. When performing power generation, the auxiliary motor 5generates an alternating current, and the inverter 511 may convert thealternating current generated by the auxiliary motor 5 during powergeneration into a high-voltage direct current, for example, a 600Vhigh-voltage direct current, so as to supply power to at least one ofthe power motor 2 and the DC-DC converter 4.

It may be understood that, the second controller 21 may have a DC-ACconversion unit, and the DC-AC conversion unit may convert thehigh-voltage direct current output by the inverter 511 into analternating current, so as to charge the power motor 4.

Specifically, as shown in FIG. 12, the inverter 511 of theauxiliary-motor controller 51 has a first direct-current end DC1, thesecond controller 21 has a second direct-current end DC2, and the DC-DCconverter 4 has a third direct-current end DC3. The first direct-currentend DC1 of the auxiliary-motor controller 51 is connected to the thirddirect-current end DC3 of the DC-DC converter 4 through the voltagestabilization circuit 300, so as to provide a stabilized voltage to theDC-DC converter 4, and the DC-DC converter 4 may perform DC-DCconversion on a direct current after voltage stabilization. Moreover,the inverter 511 of the auxiliary-motor controller 51 may further outputa high-voltage direct current to the second controller 21 through thefirst direct-current end DC1 to supply power to the power motor 2.

Further, as shown in FIG. 12, the DC-DC converter 4 is further connectedto an electric appliance device 10 and a low-voltage storage battery 20in the hybrid power automobile to supply power to the electric appliancedevice 10 and the low-voltage storage battery 20, and the low-voltagestorage battery 20 is further connected to the electric appliance device10.

Specifically, as shown in FIG. 12, the DC-DC converter 4 further has afourth direct current end DC4, and the DC-DC converter 4 may convert ahigh-voltage direct current output by the auxiliary motor 5 through theauxiliary-motor controller 51 into a low-voltage direct current, andoutput the low-voltage direct current through the fourth direct currentend DC4. The fourth direct current end DC4 of the DC-DC converter 4 isconnected to the first electric appliance device 10, so as to supplypower to the first electric appliance device 10, where the firstelectric appliance device 10 may be a low-voltage power consumptiondevice, and includes but is not limited to a lamp and a radio. Thefourth direct current end DC4 of the DC-DC converter 4 may be furtherconnected to the low-voltage storage battery 20, so as to charge thelow-voltage storage battery 20. The low-voltage storage battery 20 isconnected to the first electric appliance device 10, so as to supplypower to the first electric appliance device 10. Particularly, when theauxiliary motor 5 stops power generation, the low-voltage storagebattery 20 may supply power to the first electric appliance device 10,thereby ensuring low-voltage power consumption of the entire vehicle,ensuring that the entire vehicle may implement travelling in a pure fuelmode, and improving travelling mileage of the entire vehicle.

It should be noted that, in this embodiment of the present invention, alow voltage may be a voltage of 12 V or 24 V, a high voltage may be avoltage of 600 V, and a preset voltage range may be 11 V to 13 V or 23to 25 V, but this embodiment is not limited thereto.

To sum up, the power system of a hybrid power automobile of thisembodiment of the present invention not only can maintain low-speedelectric balance and low-speed smoothness of the entire vehicle, butalso can ensure normal operating of the DC-DC converter when the powerbattery is invalid or is damaged and disconnected from the DC-DCconverter; and has high control precision and a small loss.

Moreover, an embodiment of the present invention further proposes ahybrid power automobile.

FIG. 13 is a schematic block diagram of a hybrid power automobileaccording to an embodiment of the present invention. As shown in FIG.13, the hybrid power automobile 200 includes the power system 100 of ahybrid power automobile of the foregoing embodiment.

According to the hybrid power automobile proposed in this embodiment ofthe present invention, low-speed electric balance and low-speedsmoothness of the entire vehicle can be maintained.

Based on the hybrid power automobile and the power system thereof of theforegoing embodiments, an embodiment of the present invention furtherproposes a power generation control method for a hybrid powerautomobile.

FIG. 14 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention. As shown in FIG. 14, the power generation controlmethod for a hybrid power automobile includes the following steps:

S1: Obtain an SOC value of a power battery and an SOC value of alow-voltage storage battery of the hybrid power automobile.

It should be noted that, the SOC value of the power battery and the SOCvalue of the low-voltage storage battery may be collected through abattery management system of the hybrid power automobile, so as toobtain the SOC value of the power battery and the SOC value of thelow-voltage storage battery.

S2: Obtain a maximum allowed power generation power of an auxiliarymotor of the hybrid power automobile.

According to a specific example of the present invention, the maximumallowed power generation power of the auxiliary motor is related toperformance parameters and the like of the auxiliary motor and anengine. In other words, the maximum allowed power generation power ofthe auxiliary motor may be preset according to the performanceparameters and the like of the auxiliary motor and the engine.

S3: Determine, according to the SOC value of the power battery, the SOCvalue of the low-voltage storage battery and the maximum allowed powergeneration power of the auxiliary motor, whether the auxiliary motorcharges the power battery and/or the low-voltage storage battery.

Therefore, by charging the power battery, power consumption requirementsof the power motor and the high-voltage electric appliance device may beensured, and further it is ensured that the power motor drives theentire vehicle to normally travel; and by charging the low-voltagestorage battery, power consumption requirements of the low-voltageelectric appliance device may be ensured, and when the auxiliary motorstops power generation and the power battery is faulty or has aninsufficient power level, low-voltage power supply of the entire vehiclemay be implemented through the low-voltage storage battery, and furtherit is ensured that the entire vehicle may travel in the pure fuel mode,thereby improving travelling mileage of the entire vehicle.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is less than a first preset SOC value andthe SOC value of the low-voltage storage battery is greater than orequal to a second preset SOC value, the engine of the hybrid powerautomobile is controlled to drive the auxiliary motor to perform powergeneration to charge the power battery.

It should be understood that, the first preset SOC value may be acharging limit value of the power battery, the second preset SOC valuemay be a charging limit value of the low-voltage storage battery, andthe first preset SOC value and the second preset SOC value may beindependently set according to performance of the batteries.

Specifically, after the SOC value of the power battery and the SOC valueof the low-voltage storage battery are obtained, whether the SOC valueof the power battery is less than the first preset SOC value may bedetermined, and whether the SOC value of the low-voltage storage batteryis less than the second preset SOC value may be determined. If the SOCvalue of the power battery is less than the first preset SOC value andthe SOC value of the low-voltage storage battery is greater than orequal to the second preset SOC value, it indicates that the powerbattery has a relatively low remaining power level and needs to becharged, and the low-voltage storage battery has a relatively highremaining power level and does not need to be charged. In this case, acontrol module controls the engine to drive the auxiliary motor toperform power generation to charge the power battery.

As described above, the auxiliary motor belongs to a high-voltage motor.For example, a power generation voltage of the auxiliary motor isequivalent to a voltage of the power battery, and therefore electricenergy generated by the auxiliary motor may directly charge the powerbattery without voltage conversion.

Similarly, when the SOC value of the power battery is greater than orequal to the first preset SOC value and the SOC value of the low-voltagestorage battery is less than the second preset SOC value, the engine ofthe hybrid power automobile is controlled to drive the auxiliary motorto perform power generation to charge the low-voltage storage batterythrough a DC-DC converter of the hybrid power automobile.

To be specific, if the SOC value of the power battery is greater than orequal to the first preset SOC value and the SOC value of the low-voltagestorage battery is less than the second preset SOC value, it indicatesthe power battery has a relatively high remaining power level and doesnot need to be charged, and the low-voltage storage battery has arelatively low remaining power level and needs to be charged. In thiscase, the control module controls the engine to drive the auxiliarymotor to perform power generation to charge the low-voltage storagebattery through the DC-DC converter.

As described above, the auxiliary motor belongs to a high-voltage motor.For example, a power generation voltage of the auxiliary motor isequivalent to a voltage of the power battery, and therefore electricenergy generated by the auxiliary motor needs to be subjected to voltageconversion through the DC-DC converter and then charge the low-voltagestorage battery.

Furthermore, according to an embodiment of the present invention, whenthe SOC value of the power battery is less than the first preset SOCvalue and the SOC value of the low-voltage storage battery is less thanthe second preset SOC value, a charging power of the power battery isobtained according to the SOC value of the power battery, and a chargingpower of the low-voltage storage battery is obtained according to theSOC value of the low-voltage storage battery; and when a sum of thecharging power of the power battery and the charging power of thelow-voltage storage battery is greater than the maximum allowed powergeneration power of the auxiliary motor, the engine of the hybrid powerautomobile is controlled to drive the auxiliary motor to perform powergeneration to charge the low-voltage storage battery through the DC-DCconverter of the hybrid power automobile.

Moreover, when the sum of the charging power of the power battery andthe charging power of the low-voltage storage battery is less than orequal to the maximum allowed power generation power of the auxiliarymotor, the engine is controlled to drive the auxiliary motor to performpower generation to charge the power battery, and to simultaneouslycharge the low-voltage storage battery through the DC-DC converter.

To be specific, if the SOC value of the power battery is less than thefirst preset SOC value and the SOC value of the low-voltage storagebattery is less than the second preset SOC value, it indicates that thepower battery and the low-voltage storage battery each have a relativelylow remaining power level, and need to be charged. In this case, whetherthe sum of the charging power of the power battery and the chargingpower of the low-voltage storage battery is greater than the maximumallowed power generation power of the auxiliary motor is furtherdetermined.

If the sum of the charging power of the power battery and the chargingpower of the low-voltage storage battery is greater than the maximumallowed power generation power of the auxiliary motor, it indicates thatthe electric energy that can be generated by the auxiliary motor isinsufficient to simultaneously charge the two batteries. In this case,the low-voltage storage battery is preferentially charged, that is, theengine is controlled to drive the auxiliary motor to perform powergeneration to charge the low-voltage storage battery through the DC-DCconverter.

If the sum of the charging power of the power battery and the chargingpower of the low-voltage storage battery is less than or equal to themaximum allowed power generation power of the auxiliary motor, itindicates that the electric energy that can be generated by theauxiliary motor can simultaneously charge the two batteries. In thiscase, the power battery and the low-voltage storage battery aresimultaneously charged, that is, the engine is controlled to drive theauxiliary motor to perform power generation to charge the power battery,and simultaneously charge the low-voltage storage battery through theDC-DC converter.

Therefore, by preferentially charging the low-voltage storage battery,power consumption requirements of the low-voltage electric appliancedevice may be preferentially ensured, and further it may be ensured thatthe entire vehicle travels in the pure fuel mode when the power batteryhas an insufficient power level, thereby improving travelling mileage ofthe entire vehicle.

Certainly, it should be understood that, when the SOC value of the powerbattery is greater than or equal to the first preset SOC value and theSOC value of the low-voltage storage battery is greater than or equal tothe second preset SOC value, it indicates that the power battery and thelow-voltage storage battery each have a relatively high remaining powerlevel, and do not need to be charged. In this case, the power batteryand the low-voltage storage battery may be not charged.

Specifically, as shown in FIG. 15, a power generation control method fora hybrid power automobile of an embodiment of the present inventionspecifically includes the following steps:

S101: Obtain an SOC value of a power battery and an SOC value of alow-voltage storage battery.

S102: Determine whether the SOC value of the power battery is less thana first preset SOC value.

If yes, step S105 is performed; or if not, step S103 is performed.

S103: Determine whether the SOC value of the low-voltage storage batteryis less than a second preset SOC value.

If yes, step S104 is performed; or if not, the process returns to stepS101.

S104: Charge the low-voltage storage battery, that is, control an engineto drive an auxiliary motor to perform power generation to charge thelow-voltage storage battery through a DC-DC converter.

S105: Determine whether the SOC value of the low-voltage storage batteryis less than a second preset SOC value.

If yes, step S107 is performed; or if not, step S106 is performed.

S106: Charge the power battery, that is, control the engine to drive theauxiliary motor to perform power generation to charge the power battery.

S107: Obtain a charging power of the power battery and a charging powerof the low-voltage storage battery.

S108: Determine whether a sum of the charging power of the power batteryand the charging power of the low-voltage storage battery is greaterthan a maximum allowed power generation power of the auxiliary motor.

If yes, step S109 is performed; or if not, step S110 is performed.

S109: Charge the low-voltage storage battery preferentially, that is,control the engine to drive the auxiliary motor to perform powergeneration to charge the low-voltage storage battery through the DC-DCconverter.

S110: Charge the power battery and the low-voltage storage batterysimultaneously, that is, control the engine to drive the auxiliary motorto perform power generation to charge the power battery, andsimultaneously charge the low-voltage storage battery through the DC-DCconverter.

To sum up, according to the power generation control method for a hybridpower automobile proposed in this embodiment of the present invention,whether the auxiliary motor charges the power battery and/or thelow-voltage storage battery is determined according to the SOC value ofthe power battery, the SOC value of the low-voltage storage battery andthe maximum allowed power generation power of the auxiliary motor.Therefore, the method not only may charge the power battery, but alsomay charge the low-voltage storage battery. Therefore, power consumptionrequirements of the power motor and the high-voltage electric appliancedevice may be ensured, and further it is ensured that the power motordrives the entire vehicle to normally travel; and power consumptionrequirements of the low-voltage electric appliance device may beensured, and further when the auxiliary motor stops power generation andthe power battery is faulty or has an insufficient power level, it maybe ensured that the entire vehicle may travel in the pure fuel mode,thereby improving travelling mileage of the entire vehicle.

Based on the hybrid power automobile and the power system thereof of theforegoing embodiments, an embodiment of the present invention furtherproposes another power generation control method for a hybrid powerautomobile.

FIG. 16 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention. As shown in FIG. 16, the power generation controlmethod for a hybrid power automobile includes the following steps:

S10: Obtain an SOC value of a power battery and a speed of the hybridpower automobile.

It should be noted that, the SOC value of the power battery may becollected through a battery management system of the hybrid powerautomobile, so as to obtain the SOC value of the power battery.

S20: control, according to the SOC value of the power battery and thespeed of the hybrid power automobile, an auxiliary motor to enter apower generation power adjustment mode, so that an engine runs in apreset optimal economical area.

It should be further noted that, the preset optimal economical area ofthe engine may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine, a horizontalcoordinate indicates a rotational speed of the engine, and a curve a isa fuel economy curve of the engine. An area corresponding to the fueleconomy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine are locatedon an optimal fuel economy curve of the engine, the engine is located inthe optimal economical area. Therefore, in this embodiment of thepresent invention, the engine may be enabled, by controlling therotational speed and the output torque of the engine to fall on the fueleconomy curve of the engine, for example, the curve a, to run in thepreset optimal economical area.

Further, according to an embodiment of the present invention, when thehybrid power automobile is travelling, the SOC value of the powerbattery and the speed V of the hybrid power automobile are obtained, andthe auxiliary motor is controlled according to the SOC value of thepower battery and the speed V of the hybrid power automobile to enterthe power generation power adjustment mode, so that the engine runs inthe preset optimal economical area. The power generation poweradjustment mode is a mode of adjusting a power generation power of theengine, and in the power generation power adjustment mode, the powergeneration power of the auxiliary motor 5 may be adjusted by controllingthe engine 1 to drive the auxiliary motor 5 to perform power generation.

Specifically, when the hybrid power automobile is travelling, the enginemay output power to wheels of the hybrid power automobile through aclutch, and the engine may further drive the auxiliary motor to performpower generation. Therefore, the output power of the engine mainlyincludes two parts, one part is output to the auxiliary motor, that is,the power for driving the auxiliary motor to perform power generation,and the other part is output to the wheels, that is, the power fordriving the wheels.

When the engine drives the auxiliary motor to perform power generation,the SOC value of the power battery and the speed of the hybrid powerautomobile may be first obtained, and then the auxiliary motor iscontrolled according to the SOC value of the power battery and the speedof the hybrid power automobile to enter the power generation poweradjustment mode, so that the engine operates in the preset optimaleconomical area. In the power generation power adjustment mode, thepower generation power of the auxiliary motor may be adjusted on thepremise of enabling the engine to operate in the preset optimaleconomical area.

Therefore, the engine is enabled to operate in the preset optimaleconomical area, and because the engine has lowest fuel consumption andhighest fuel economy in the preset optimal economical area, fuelconsumption of the engine may be reduced, noise of the engine may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than a preset limit value andis less than or equal to a first preset value, if the speed V of thehybrid power automobile is less than a first preset speed, the auxiliarymotor is controlled to enter the power generation power adjustment mode.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery, for example, a value of determining to stopcharging, and may be preferably 30%. The preset limit value may be apreset lower limit value of the SOC value of the power battery, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power batteryis less than or equal to the preset limit value, the SOC value of thepower battery falls within the first power level range. In this case,the power battery performs only charging but does not performdischarging. When the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the SOC value of the power battery falls within the second power levelrange. In this case, the power battery has a charging requirement, thatis, the power battery may be actively charged. When the SOC value of thepower battery is greater than the first preset value, the SOC value ofthe power battery falls within the third power level range. In thiscase, the power battery may be not charged, that is, the power batteryis not actively charged.

Specifically, after the SOC value of the power battery and the speed Vof the hybrid power automobile are obtained, a range within which theSOC value of the power battery falls may be determined. If the SOC valueof the power battery falls within the second power level range, and theSOC value of the power battery is greater than the preset limit valueand is less than or equal to the first preset value, it indicates thatthe power battery may be charged. In this case, whether the speed V ofthe hybrid power automobile is less than the first preset speed V1 isfurther determined. If the speed V of the hybrid power automobile isless than the first preset speed V1, the auxiliary motor is controlledto enter the power generation power adjustment mode. In this case, thespeed of the hybrid power automobile is relatively low, a needed driveforce is relatively small, the power motor is sufficient to drive thehybrid power automobile to travel, and the engine may drive only theauxiliary motor to perform power generation, but does not participate indrive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than the preset limit value M2and is less than or equal to the first preset value M1, and the speed Vof the hybrid power automobile is less than the first preset speed V1,an entire vehicle requirement power P2 of the hybrid power automobile isfurther obtained; and when the entire vehicle requirement power P2 isless than or equal to a maximum allowed power generation power Pmax ofthe auxiliary motor, the auxiliary motor is controlled to enter thepower generation power adjustment mode.

Specifically, when the hybrid power automobile is travelling, if the SOCvalue of the power battery is greater than the preset limit value M2 andis less than or equal to the first preset value M1, and the speed V ofthe hybrid power automobile is less than the first preset speed V1, thatis, the speed of the hybrid power automobile is relatively low, theentire vehicle requirement power P2 of the hybrid power automobile isobtained; and when the entire vehicle requirement power P2 is less thanor equal to the maximum allowed power generation power Pmax of theauxiliary motor, the auxiliary motor is controlled to enter the powergeneration power adjustment mode.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, according to an embodiment of the present invention, whenthe SOC value of the power battery is greater than the preset limitvalue and is less than or equal to the first preset value M1, the speedV of the hybrid power automobile is less than the first preset speed V1,and the entire vehicle requirement power P2 is less than or equal to themaximum allowed power generation power Pmax of the auxiliary motor, anaccelerator pedal depth D of the hybrid power automobile and an entirevehicle resistance F of the hybrid power automobile are furtherobtained; and when the accelerator pedal depth D is less than or equalto a first preset depth D1 and the entire vehicle resistance F of thehybrid power automobile is less than or equal to a first presetresistance F1, the auxiliary motor is controlled to enter the powergeneration power adjustment mode.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

Specifically, if the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset valueM1, the speed V of the hybrid power automobile is less than the firstpreset speed V1, and the entire vehicle requirement power P2 is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor, the accelerator pedal depth D of the hybrid powerautomobile and the entire vehicle resistance F of the hybrid powerautomobile are obtained in real time; and when the accelerator pedaldepth D is less than or equal to the first preset depth D1 and theentire vehicle resistance F of the hybrid power automobile is less thanor equal to the first preset resistance F1, indicating that the hybridpower automobile runs in a low speed mode, the auxiliary motor iscontrolled to enter the power generation power adjustment mode.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

Correspondingly, when the SOC value of the power battery, the speed V,the accelerator pedal depth D and the entire vehicle resistance F of thehybrid power automobile do not satisfy the foregoing conditions, theengine may participate in drive, and a specific operating processthereof is as follows:

According to an embodiment of the present invention, when the SOC valueof the power battery is less than the preset limit value, the speed ofthe hybrid power automobile is greater than or equal to the first presetspeed, the entire vehicle requirement power is greater than the maximumallowed power generation power of the auxiliary motor, the acceleratorpedal depth is greater than the first preset depth, or the entirevehicle resistance of the hybrid power automobile is greater than thefirst preset resistance, the engine is controlled to participate indrive.

To be specific, when the SOC value of the power battery is less than thepreset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, theengine is controlled to participate in drive. In this case, the powerbattery does not perform discharging again, the entire vehicle needs arelatively large drive force, the entire vehicle requirement power isrelatively large, the accelerator pedal depth is relatively large or theentire vehicle resistance is also relatively large, the power motor isinsufficient to drive the hybrid power automobile to travel, and theengine participates in drive to perform supplemental drive.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, when the entire vehicle requirement power is greaterthan the maximum allowed power generation power of the auxiliary motor,the engine is further controlled to participate in drive to enable theengine to output power to wheels through the clutch.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value M2, the engine is further controlled toparticipate in drive to enable the engine to output power to wheelsthrough the clutch; when the SOC value of the power battery is less thanor equal to the first preset value M1, the speed V of the hybrid powerautomobile is less than the first preset speed V1 and the acceleratorpedal depth D is greater than the first preset depth D1, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch; and when the SOC value ofthe power battery is less than or equal to the first preset value M1,the speed V of the hybrid power automobile is less than the first presetspeed V1 and the entire vehicle resistance F of the hybrid powerautomobile is greater than the first preset resistance F1, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch.

Specifically, when the engine drives the auxiliary motor to performpower generation and the power motor outputs a drive force to the wheelsof the hybrid power automobile, the SOC value of the power battery, theaccelerator pedal depth D of the hybrid power automobile, the speed Vand the entire vehicle resistance F are obtained in real time, and theSOC value of the power battery, the accelerator pedal depth D of thehybrid power automobile, the speed V and the entire vehicle resistance Fare determined; and the power generation power of the auxiliary motor isadjusted according to the following three determining results:

First, when the SOC value of the power battery is less than the presetlimit value M2, the engine is controlled to output power to the wheelsthrough the clutch, so that the engine and the power motorsimultaneously participate in drive, and load of the power motor isreduced to reduce power consumption of the power battery, therebyensuring that the engine operates in the preset optimal economical areaand preventing the SOC value of the power battery from quick decreasing.

Second, when the SOC value of the power battery is less than or equal tothe first preset value M1, the speed V of the hybrid power automobile isless than the first preset speed V1 and the accelerator pedal depth D isgreater than the first preset depth D1, the engine is controlled tooutput power to the wheels through the clutch, so that the engine andthe power motor simultaneously participate in drive, and load of thepower motor is reduced to reduce power consumption of the power battery,thereby ensuring that the engine operates in the preset optimaleconomical area and preventing the SOC value of the power battery fromquick decreasing.

Third, when the SOC value of the power battery is less than or equal tothe first preset value M1, the speed V of the hybrid power automobile isless than the first preset speed V1 and the resistance F of the hybridpower automobile is greater than the first preset resistance F1, theengine is controlled to output power to the wheels through the clutch,so that the engine and the power motor simultaneously participate indrive, and load of the power motor is reduced to reduce powerconsumption of the power battery, thereby ensuring that the engineoperates in the preset optimal economical area and preventing the SOCvalue of the power battery from quick decreasing.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value, and the speed of the hybrid power automobileis greater than the first preset speed, the engine is controlled toparticipate in drive to enable the engine to output power to the wheelsthrough the clutch.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, when the SOC value of the powerbattery is greater than the first preset value, the engine does notdrive the auxiliary motor to perform power generation. In this case, thepower battery has an approximately full power level, and does not needto be charged, and the engine does not drive the auxiliary motor toperform power generation. To be specific, when the power battery has anapproximately full power level, the engine does not drive the auxiliarymotor to perform power generation, and therefore the auxiliary motordoes not charge the power battery.

Further, after the auxiliary motor enters the power generation poweradjustment mode, the power generation power of the auxiliary motor maybe adjusted. A process of adjusting the power generation power of thisembodiment of the present invention is specifically described below.

According to an embodiment of the present invention, after the auxiliarymotor enters the power generation power adjustment mode, a powergeneration power P1 of the auxiliary motor is adjusted according to theentire vehicle requirement power P2 of the hybrid power automobile and acharging power P3 of the power battery.

According to an embodiment of the present invention, a formula ofadjusting the power generation power P1 of the auxiliary motor accordingto the entire vehicle requirement power P2 of the hybrid powerautomobile and the charging power P3 of the power battery is as follows:

P1=P2+P3, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices include a firstelectric appliance device and a second electric appliance device, thatis, the electric appliance device power P21 may include power needed bythe high-voltage electric appliance device and the low-voltage electricappliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor, and the entire vehicledrive power P11 may be obtained according to a presetaccelerator-torsional moment curve of the power motor and a rotationalspeed of the power motor, where the preset accelerator-torsional momentcurve may be determined during power matching of the hybrid powerautomobile. Moreover, the electric appliance device power P21 may beobtained in real time according to electric appliance devices running onthe entire vehicle, for example, the electric appliance device power P21is calculated through DC consumption on a bus. Moreover, the chargingpower P3 of the power battery may be obtained according to the SOC valueof the power battery. Assuming that the entire vehicle drive power P11obtained in real time is equal to b1 kw, the electric appliance devicepower P21 is equal to b2 kw, and the charging power P3 of the powerbattery is equal to b3 kw, the power generation power of the auxiliarymotor is equal to b1+b2+b3.

Specifically, when the hybrid power automobile is travelling, thecharging power P3 of the power battery, the entire vehicle drive powerP11 and the electric appliance device power P21 may be obtained, and asum of the charging power P3 of the power battery, the entire vehicledrive power P11 and the electric appliance device power P21 is used asthe power generation power P1 of the auxiliary motor. Therefore, thepower generation power of the auxiliary motor may be adjusted accordingto the calculated P1 value. For example, the output torque and therotational speed of the engine may be controlled according to thecalculated P1 value, so as to adjust the power for the engine to drivethe auxiliary motor to perform power generation.

Further, according to an embodiment of the present invention, theadjusting the power generation power of the auxiliary motor includes:obtaining an SOC value change rate of the power battery, and adjustingthe power generation power of the auxiliary motor according to arelationship between the entire vehicle requirement power P2 and aminimum output power Pmin corresponding to the optimal economical areaof the engine, and the SOC value change rate of the power battery.

It should be understood that, the SOC value change rate of the powerbattery may be obtained according to the SOC value of the power battery,for example, the SOC value of the power battery is collected once ateach time interval t. In this way, a ratio of a difference between acurrent SOC value and a former SOC value of the power battery to thetime interval t may be used as the SOC value change rate of the powerbattery 3.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After the minimumoutput power Pmin corresponding to the optimal economical area of theengine is determined, the power generation power of the auxiliary motor5 may be adjusted according to the relationship between the entirevehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine, and the SOCvalue change rate of the power battery.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine may perform only power generation but does not participate indrive, and because the engine does not participate in drive, the clutchdoes not need to be used, thereby reducing abrasion or slip friction ofthe clutch, reducing an unsmooth feeling, and improving comfortableness,so as to maintain low-speed electric balance and low-speed smoothness ofthe entire vehicle and improve performance of the entire vehicle.

A specific adjusting manner in which after the auxiliary motor entersthe power generation power adjustment mode, the power generation powerof the auxiliary motor is adjusted according to the relationship betweenthe entire vehicle requirement power P2 and the minimum output powerPmin corresponding to the optimal economical area of the engine, and theSOC value change rate of the power battery is further described below.

Specifically, when the engine drives the auxiliary motor to performpower generation and the power motor outputs a drive force to the wheelsof the hybrid power automobile, the entire vehicle drive power P11 andthe electric appliance device power P21 are obtained in real time, so asto obtain the entire vehicle requirement power P2 of the hybrid powerautomobile, and the entire vehicle requirement power P2 of the hybridpower automobile is determined, where the entire vehicle requirementpower P2 may satisfy the following three cases.

In a first case, the entire vehicle requirement power P2 is less thanthe minimum output power Pmin corresponding to the optimal economicalarea of the engine; in a second case, the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor; and in a third case, the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor.

In an embodiment of the first case, when the entire vehicle requirementpower P2 is less than the minimum output power Pmin corresponding to theoptimal economical area of the engine, the charging power P3 of thepower battery is obtained according to the SOC value change rate of thepower battery, and whether the charging power P3 of the power battery isless than the difference between the minimum output power Pmin and theentire vehicle requirement power P2 is determined. If the charging powerP3 of the power battery is less than the difference between the minimumoutput power Pmin and the entire vehicle requirement power P2, theengine is controlled to perform power generation at the minimum outputpower Pmin to adjust the power generation power of the auxiliary motor;or if the charging power P3 of the power battery is greater than orequal to the difference between the minimum output power Pmin and theentire vehicle requirement power P2, an output power of the engine inthe preset optimal economical area is obtained according to a sum of thecharging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to adjust the power generationpower P1 of the auxiliary motor.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery and the charging power P3 of thepower battery may be pre-stored. Therefore, after an SOC value changerate of the power battery is obtained, a corresponding charging power P3of the power battery may be obtained by performing matching on the firstrelationship table. The SOC value change rate of the power battery andthe charging power P3 of the power battery satisfy a relationship shownin Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power P3 of the power B1 B2 B3 B4 B5 battery 3

It is learned from Table 1 that, when an obtained SOC value change rateis A1, an obtained corresponding charging power P3 of the power batteryis B1; when an obtained SOC value change rate is A2, an obtainedcorresponding charging power P3 of the power battery is B2; when anobtained SOC value change rate is A3, an obtained corresponding chargingpower P3 of the power battery is B3; when an obtained SOC value changerate is A4, an obtained corresponding charging power P3 of the powerbattery is B4; and when an obtained SOC value change rate is A5, anobtained corresponding charging power P3 of the power battery is B5.

Specifically, after the auxiliary motor enters the power generationpower adjustment mode, the entire vehicle drive power P11 and theelectric appliance device power P21 are obtained in real time, so as toobtain the entire vehicle requirement power P2 of the hybrid powerautomobile, and the entire vehicle requirement power P2 of the hybridpower automobile is determined. When the entire vehicle requirementpower P2 is less than the minimum output power Pmin corresponding to theoptimal economical area of the engine, the charging power P3 of thepower battery may be obtained according to the SOC value change rate ofthe power battery, and whether the charging power P3 of the powerbattery is less than the difference between the minimum output powerPmin and the entire vehicle requirement power P2 is determined.

When the entire vehicle requirement power P2 is less than the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1, if the charging power P3 of the power battery is less than thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, that is, P3<Pmin−P2, the engine is controlled toperform power generation at the minimum output power Pmin to adjust thepower generation power of the auxiliary motor 1. If the charging powerP3 of the power battery is greater than or equal to the differencebetween the minimum output power Pmin and the entire vehicle requirementpower P2, that is, P3≥Pmin−P2, the output power of the engine in thepreset optimal economical area is obtained according to the sum of thecharging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to adjust the power generationpower of the auxiliary motor.

Therefore, when the entire vehicle requirement power P2 is less than theminimum output power Pmin corresponding to the optimal economical areaof the engine, the power generation power of the engine is obtainedaccording to the relationship between the charging power P3 of the powerbattery and the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine and theentire vehicle requirement power P2, so that the engine runs in thepreset optimal economical area, and the engine performs only powergeneration but does not participate in drive, thereby reducing fuelconsumption of the engine, and reducing noise of the engine.

In an embodiment of the second case, when the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor, the charging power P3 of the power battery is obtainedaccording to the SOC value change rate of the power battery, an outputpower of the engine in the preset optimal economical area is obtainedaccording to a sum of the charging power P3 of the power battery and theentire vehicle requirement power P2, and the engine is controlled toperform power generation at the obtained output power to adjust thepower generation power P1 of the auxiliary motor.

Specifically, when the entire vehicle requirement power P2 is greaterthan or equal to the minimum output power Pmin corresponding to theoptimal economical area of the engine and is less than the maximumallowed power generation power Pmax of the auxiliary motor, the chargingpower P3 of the power battery is further obtained according to the SOCvalue change rate of the power battery when the engine is controlled tooperate in the preset optimal economical area, and the output power ofthe engine in the preset optimal economical area is obtained accordingto the sum of the charging power P3 of the power battery and the entirevehicle requirement power P2, where the obtained output power is equalto P3+P2. Then, the engine is controlled to perform power generation atthe obtained output power to adjust the power generation power P1 of theauxiliary motor, thereby increasing the SOC value of the power battery,and enabling the engine to operate in the preset optimal economicalarea.

Therefore, when the entire vehicle requirement power P2 is greater thanor equal to the minimum output power Pmin corresponding to the optimaleconomical area of the engine and is less than the maximum allowed powergeneration power Pmax of the auxiliary motor, the output power of theengine is obtained according to the sum of the charging power P3 of thepower battery and the entire vehicle requirement power P2, so that theengine runs in the preset optimal economical area, and the engineperforms only power generation but does not participate in drive,thereby reducing fuel consumption of the engine, and reducing noise ofthe engine.

In an embodiment of the third case, when the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor, the engine is further controlled to participatein drive to enable the engine to output power to wheels through theclutch.

Specifically, when the entire vehicle requirement power P2 is greaterthan the maximum allowed power generation power Pmax of the auxiliarymotor, that is, the entire vehicle requirement power P2 of the hybridpower automobile is greater than the power generation power P1 of theauxiliary motor, the engine is further controlled to output a driveforce to the wheels through the clutch to enable the engine toparticipate in drive. Therefore, the engine undertakes a part of a drivepower P, so as to reduce a requirement of the auxiliary motor on thepower generation power P1, so that the engine operates in the presetoptimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanthe maximum allowed power generation power Pmax of the auxiliary motor,the power battery discharges outward to supply power to the power motor.In this case, the engine and the power motor are controlled tosimultaneously output power to the wheels of the hybrid powerautomobile, so that the engine operates in the preset optimal economicalarea.

As described above, as shown in FIG. 17, a power generation controlmethod for a hybrid power automobile of an embodiment of the presentinvention specifically includes the following steps:

S201: Obtain an SOC value M of a power battery and a speed V of thehybrid power automobile.

S202: Determine whether the speed V of the hybrid power automobile isless than a first preset speed V1.

If yes, step S203 is performed; or if not, step S204 is performed.

S203: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S207 is performed; or if not, step S206 is performed.

S204: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S205 is performed; or if not, step S206 is performed.

S205: Control an engine to participate in drive.

S206: Control the engine not to drive an auxiliary motor to performpower generation.

S207: Obtain an accelerator pedal depth D of the hybrid power automobileand an entire vehicle resistance F of the hybrid power automobile.

S208: Determine whether the accelerator pedal depth D is greater than afirst preset depth D1, whether the entire vehicle resistance F of thehybrid power automobile is greater than a first preset resistance F1, orwhether the SOC value M of the power battery is less than a preset limitvalue M2.

If yes, step S205 is performed; or if not, step S209 is performed.

S209: Obtain an entire vehicle requirement power P2 of the hybrid powerautomobile.

S210: Determine whether the entire vehicle requirement power P2 is lessthan or equal to a maximum allowed power generation power Pmax of theauxiliary motor.

If yes, step S211 is performed; or if not, step S205 is performed.

S211: Control the engine to drive the auxiliary motor to perform powergeneration, and the engine not to participate in drive.

In this case, the auxiliary motor is controlled to enter a powergeneration power adjustment mode.

S212: Determine whether the entire vehicle requirement power P2 is lessthan a minimum output power Pmin corresponding to an optimal economicalarea of the engine.

If yes, step S213 is performed; or if not, step S214 is performed.

S213: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery, and perform step S215.

S214: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery, and perform step S216.

S215: Determine whether the charging power P3 of the power battery isless than a difference between the minimum output power Pmin and theentire vehicle requirement power P2.

If yes, step S217 is performed; or if not, step S216 is performed.

S216: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery and the entire vehicle requirement power P2, and control theengine to perform power generation at the obtained output power.

S217: Control the engine to perform power generation at the minimumoutput power Pmin.

To sum up, according to the power generation control method for a hybridpower automobile of this embodiment of the present invention, the SOCvalue of the power battery and the speed of the hybrid power automobileare first obtained, and the auxiliary motor is controlled according tothe SOC value of the power battery and the speed of the hybrid powerautomobile to enter the power generation power adjustment mode, so thatthe engine runs in the preset optimal economical area, thereby reducingfuel consumption of the engine, improving running economy of the entirevehicle, reducing noise of the engine, implementing a plurality of drivemodes, maintaining low-speed electric balance and low-speed smoothnessof the entire vehicle, and improving performance of the entire vehicle.

Based on the hybrid power automobile and the power system thereof of theforegoing embodiments, an embodiment of the present invention furtherproposes still another power generation control method for a hybridpower automobile.

FIG. 18 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention. As shown in FIG. 18, the power generation controlmethod for a hybrid power automobile includes the following steps:

S100: Obtain an SOC value of a power battery and a speed of the hybridpower automobile.

It should be noted that, the SOC value of the power battery may becollected through a battery management system of the hybrid powerautomobile, so as to obtain the SOC value of the power battery.

S200: Control a power generation power P1 of an auxiliary motoraccording to the SOC value of the power battery and the speed of thehybrid power automobile.

S300: Obtain a power generation power of an engine of the hybrid powerautomobile according to the power generation power of the auxiliarymotor, so as to control the engine to run in a preset optimal economicalarea, where the auxiliary motor performs power generation under drivingof the engine.

It should be further noted that, the preset optimal economical area ofthe engine may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine, a horizontalcoordinate indicates a rotational speed of the engine, and a curve a isa fuel economy curve of the engine. An area corresponding to the fueleconomy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine are locatedon an optimal fuel economy curve of the engine, the engine is located inthe optimal economical area. Therefore, in this embodiment of thepresent invention, the engine may be enabled, by controlling therotational speed and the output torque of the engine to fall on the fueleconomy curve of the engine, for example, the curve a, to run in thepreset optimal economical area.

Further, according to an embodiment of the present invention, when thehybrid power automobile is travelling, the SOC value of the powerbattery and the speed V of the hybrid power automobile are obtained, thepower generation power P1 of the auxiliary motor is controlled accordingto the SOC value of the power battery and the speed V of the hybridpower automobile, and the power generation power P0 of the engine 1 isobtained according to the power generation power P1 of the auxiliarymotor to control the engine to run in the preset optimal economicalarea.

Specifically, when the hybrid power automobile is travelling, the enginemay output power to wheels of the hybrid power automobile through aclutch, and the engine may further drive the auxiliary motor to performpower generation. Therefore, the output power of the engine mainlyincludes two parts, one part is output to the auxiliary motor, that is,the power for driving the auxiliary motor to perform power generation,and the other part is output to the wheels, that is, the power fordriving the wheels.

When the engine drives the auxiliary motor to perform power generation,the SOC value of the power battery 3 and the speed of the hybrid powerautomobile may be first obtained, the power generation power P1 of theauxiliary motor is then controlled according to the SOC value of thepower battery 3 and the speed of the hybrid power automobile, and thepower generation power P0 of the engine 1 is obtained according to thepower generation power P1 of the auxiliary motor to control the engineto run in the preset optimal economical area. Power for the engine todrive the auxiliary motor to perform power generation is determined onthe premise of enabling the engine to operate in the preset optimaleconomical area, thereby adjusting the power generation power P1 of theauxiliary motor.

Therefore, the engine is enabled to operate in the preset optimaleconomical area, and because the engine has lowest fuel consumption andhighest fuel economy in the preset optimal economical area, fuelconsumption of the engine may be reduced, noise of the engine may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than a preset limit value andis less than or equal to a first preset value, if the speed V of thehybrid power automobile is less than a first preset speed V1, the powergeneration power P1 of the auxiliary motor is controlled.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery, for example, a value of determining to stopcharging, and may be preferably 30%. The preset limit value may be apreset lower limit value of the SOC value of the power battery, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power batteryis less than or equal to the preset limit value, the SOC value of thepower battery falls within the first power level range. In this case,the power battery performs only charging but does not performdischarging. When the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the SOC value of the power battery falls within the second power levelrange. In this case, the power battery has a charging requirement, thatis, the power battery may be actively charged. When the SOC value of thepower battery is greater than the first preset value, the SOC value ofthe power battery falls within the third power level range. In thiscase, the power battery may be not charged, that is, the power batteryis not actively charged.

Specifically, after the SOC value of the power battery and the speed Vof the hybrid power automobile are obtained, a range within which theSOC value of the power battery falls may be determined. If the SOC valueof the power battery falls within the second power level range, and theSOC value of the power battery is greater than the preset limit valueand is less than or equal to the first preset value, it indicates thatthe power battery may be charged. In this case, whether the speed V ofthe hybrid power automobile is less than the first preset speed V1 isfurther determined. If the speed V of the hybrid power automobile isless than the first preset speed V1, the power generation power P1 ofthe auxiliary motor 5 is controlled. In this case, the speed of thehybrid power automobile is relatively low, a needed drive force isrelatively small, the power motor is sufficient to drive the hybridpower automobile to travel, and the engine may drive only the auxiliarymotor to perform power generation, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than the preset limit value M2and is less than or equal to the first preset value M1, and the speed Vof the hybrid power automobile is less than the first preset speed V1,an entire vehicle requirement power P2 of the hybrid power automobile isfurther obtained; and when the entire vehicle requirement power P2 isless than or equal to a maximum allowed power generation power Pmax ofthe auxiliary motor, the power generation power P1 of the auxiliarymotor is controlled.

Specifically, when the hybrid power automobile is travelling, if the SOCvalue of the power battery is greater than the preset limit value M2 andis less than or equal to the first preset value M1, and the speed V ofthe hybrid power automobile is less than the first preset speed V1, thatis, the speed of the hybrid power automobile is relatively low, theentire vehicle requirement power P2 of the hybrid power automobile isobtained; and when the entire vehicle requirement power P2 is less thanor equal to the maximum allowed power generation power Pmax of theauxiliary motor, the power generation power P1 of the auxiliary motor iscontrolled.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, according to an embodiment of the present invention, whenthe SOC value of the power battery is greater than the preset limitvalue and is less than or equal to the first preset value M1, the speedV of the hybrid power automobile is less than the first preset speed V1,and the entire vehicle requirement power P2 is less than or equal to themaximum allowed power generation power Pmax of the auxiliary motor, anaccelerator pedal depth D of the hybrid power automobile and an entirevehicle resistance F of the hybrid power automobile are furtherobtained; and when the accelerator pedal depth D is less than or equalto a first preset depth D1 and the entire vehicle resistance F of thehybrid power automobile is less than or equal to a first presetresistance F1, the power generation power P1 of the auxiliary motor iscontrolled.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

Specifically, if the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset valueM1, the speed V of the hybrid power automobile is less than the firstpreset speed V1, and the entire vehicle requirement power P2 is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor, the accelerator pedal depth D of the hybrid powerautomobile and the entire vehicle resistance F of the hybrid powerautomobile are obtained in real time; and when the accelerator pedaldepth D is less than or equal to the first preset depth D1 and theentire vehicle resistance F of the hybrid power automobile is less thanor equal to the first preset resistance F1, indicating that the hybridpower automobile runs in a low speed mode, the power generation power P1of the auxiliary motor is controlled.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine 1 may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

According to an embodiment of the present invention, when the engine iscontrolled to individually drive the auxiliary motor to perform powergeneration and the power motor is controlled to output a drive forcealone, the power generation power P0 of the engine is obtained accordingto the following formula:

P0=P1/η/ζ

where P1 represents the power generation power of the auxiliary motor, ηrepresents belt transmission efficiency, and ζ represents efficiency ofthe auxiliary motor.

To be specific, if the engine may perform only power generation but doesnot participate in drive, the power generation power P0 of the enginemay be calculated according to the power generation power of theauxiliary motor, the belt transmission efficiency η and the efficiency ζof the auxiliary motor, and the engine is controlled to drive theauxiliary motor at the obtained power generation power P0 to performpower generation, so as to control the power generation power of theauxiliary motor.

Correspondingly, when the SOC value of the power battery, the speed V,the accelerator pedal depth D and the entire vehicle resistance F of thehybrid power automobile do not satisfy the foregoing conditions, theengine may participate in drive, and a specific operating processthereof is as follows:

According to an embodiment of the present invention, when the SOC valueof the power battery is less than the preset limit value, the speed ofthe hybrid power automobile is greater than or equal to the first presetspeed, the entire vehicle requirement power is greater than the maximumallowed power generation power of the auxiliary motor, the acceleratorpedal depth is greater than the first preset depth, or the entirevehicle resistance of the hybrid power automobile is greater than thefirst preset resistance, the engine is controlled to participate indrive.

To be specific, when the SOC value of the power battery is less than thepreset limit value M2, the speed of the hybrid power automobile isgreater than or equal to the first preset speed, the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor, the accelerator pedal depth is greaterthan the first preset depth, or the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance, theengine is controlled to participate in drive. In this case, the powerbattery does not perform discharging again, the entire vehicle needs arelatively large drive force, the entire vehicle requirement power isrelatively large, the accelerator pedal depth is relatively large or theentire vehicle resistance is also relatively large, the power motor isinsufficient to drive the hybrid power automobile to travel, and theengine participates in drive to perform supplemental drive.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, when the entire vehicle requirement power is greaterthan the maximum allowed power generation power of the auxiliary motor,the engine is further controlled to participate in drive to enable theengine to output power to wheels through the clutch.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value M2, the engine is further controlled toparticipate in drive to enable the engine to output power to wheelsthrough the clutch; when the SOC value of the power battery is less thanor equal to the first preset value M1, the speed V of the hybrid powerautomobile is less than the first preset speed V1 and the acceleratorpedal depth D is greater than the first preset depth D1, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch; and when the SOC value ofthe power battery is less than or equal to the first preset value M1,the speed V of the hybrid power automobile is less than the first presetspeed V1 and the entire vehicle resistance F of the hybrid powerautomobile is greater than the first preset resistance F1, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch.

Specifically, when the engine drives the auxiliary motor to performpower generation and the power motor outputs a drive force to the wheelsof the hybrid power automobile, the SOC value of the power battery, theaccelerator pedal depth D of the hybrid power automobile, the speed Vand the entire vehicle resistance F are obtained in real time, and theSOC value of the power battery, the accelerator pedal depth D of thehybrid power automobile, the speed V and the entire vehicle resistance Fare determined; and the power generation power of the auxiliary motor isadjusted according to the following three determining results:

First, when the SOC value of the power battery is less than the presetlimit value M2, the engine is controlled to output power to the wheelsthrough the clutch, so that the engine and the power motorsimultaneously participate in drive, and load of the power motor isreduced to reduce power consumption of the power battery, therebyensuring that the engine operates in the preset optimal economical areaand preventing the SOC value of the power battery from quick decreasing.

Second, when the SOC value of the power battery is less than or equal tothe first preset value M1, the speed V of the hybrid power automobile isless than the first preset speed V1 and the accelerator pedal depth D isgreater than the first preset depth D1, the engine is controlled tooutput power to the wheels through the clutch, so that the engine andthe power motor simultaneously participate in drive, and load of thepower motor is reduced to reduce power consumption of the power battery,thereby ensuring that the engine operates in the preset optimaleconomical area and preventing the SOC value of the power battery fromquick decreasing.

Third, when the SOC value of the power battery is less than or equal tothe first preset value M1, the speed V of the hybrid power automobile isless than the first preset speed V1 and the resistance F of the hybridpower automobile is greater than the first preset resistance F1, theengine is controlled to output power to the wheels through the clutch,so that the engine and the power motor simultaneously participate indrive, and load of the power motor is reduced to reduce powerconsumption of the power battery, thereby ensuring that the engineoperates in the preset optimal economical area and preventing the SOCvalue of the power battery from quick decreasing.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value, and the speed of the hybrid power automobileis greater than the first preset speed, the engine is controlled toparticipate in drive to enable the engine to output power to the wheelsthrough the clutch.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, when the SOC value of the powerbattery is greater than the first preset value, the engine does notdrive the auxiliary motor to perform power generation. In this case, thepower battery has an approximately full power level, and does not needto be charged, and the engine does not drive the auxiliary motor toperform power generation. To be specific, when the power battery has anapproximately full power level, the engine does not drive the auxiliarymotor to perform power generation, and therefore the auxiliary motordoes not charge the power battery.

Further, after the auxiliary motor enters the power generation poweradjustment mode, the power generation power of the auxiliary motor maybe adjusted. A process of adjusting the power generation power of thisembodiment of the present invention is specifically described below.

According to an embodiment of the present invention, after the auxiliarymotor enters the power generation power adjustment mode, a powergeneration power P1 of the auxiliary motor is controlled according tothe entire vehicle requirement power P2 of the hybrid power automobileand a charging power P3 of the power battery.

According to an embodiment of the present invention, a formula ofcontrolling the power generation power P1 of the auxiliary motoraccording to the entire vehicle requirement power P2 of the hybrid powerautomobile and the charging power P3 of the power battery is as follows:

P1=P2+P3, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery, P11 is an entire vehicle drive power, and P21 is an electricappliance device power.

It should be noted that, electric appliance devices may include a firstelectric appliance device and a second electric appliance device, thatis, the electric appliance device power P21 may include power needed bythe high-voltage electric appliance device and the low-voltage electricappliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor 2, and the entire vehicledrive power P11 may be obtained according to a presetaccelerator-torsional moment curve of the power motor and a rotationalspeed of the power motor, where the preset accelerator-torsional momentcurve may be determined during power matching of the hybrid powerautomobile. Moreover, the electric appliance device power P21 may beobtained in real time according to electric appliance devices running onthe entire vehicle, for example, the electric appliance device power P21is calculated through DC consumption on a bus. Moreover, the chargingpower P3 of the power battery may be obtained according to the SOC valueof the power battery. Assuming that the entire vehicle drive power P11obtained in real time is equal to b1 kw, the electric appliance devicepower P21 is equal to b2 kw, and the charging power P3 of the powerbattery is equal to b3 kw, the power generation power of the auxiliarymotor is equal to b1+b2+b3.

Specifically, when the hybrid power automobile is travelling, thecharging power P3 of the power battery, the entire vehicle drive powerP11 and the electric appliance device power P21 may be obtained, and asum of the charging power P3 of the power battery, the entire vehicledrive power P11 and the electric appliance device power P21 is used asthe power generation power P1 of the auxiliary motor. Therefore, thepower generation power of the auxiliary motor may be controlledaccording to the calculated P1 value. For example, the output torque andthe rotational speed of the engine may be controlled according to thecalculated P1 value, so as to control the power for the engine to drivethe auxiliary motor to perform power generation.

Further, according to an embodiment of the present invention, theadjusting the power generation power of the auxiliary motor includes:obtaining an SOC value change rate of the power battery, and controllingthe power generation power of the auxiliary motor according to arelationship between the entire vehicle requirement power P2 and aminimum output power Pmin corresponding to the optimal economical areaof the engine, and the SOC value change rate of the power battery.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power Pmin corresponding to theoptimal economical area of the engine is obtained. After the minimumoutput power Pmin corresponding to the optimal economical area of theengine is determined, the power generation power of the auxiliary motor5 may be controlled according to the relationship between the entirevehicle requirement power P2 and the minimum output power Pmincorresponding to the optimal economical area of the engine, and the SOCvalue change rate of the power battery.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine may perform only power generation but does not participate indrive, and because the engine does not participate in drive, the clutchdoes not need to be used, thereby reducing abrasion or slip friction ofthe clutch, reducing an unsmooth feeling, and improving comfortableness,so as to maintain low-speed electric balance and low-speed smoothness ofthe entire vehicle and improve performance of the entire vehicle.

A specific adjusting manner in which after the auxiliary motor entersthe power generation power adjustment mode, the power generation powerof the auxiliary motor is controlled according to the relationshipbetween the entire vehicle requirement power P2 and the minimum outputpower Pmin corresponding to the optimal economical area of the engine,and the SOC value change rate of the power battery is further describedbelow.

Specifically, when the engine drives the auxiliary motor to performpower generation and the power motor outputs a drive force to the wheelsof the hybrid power automobile, the entire vehicle drive power P11 andthe electric appliance device power P21 are obtained in real time, so asto obtain the entire vehicle requirement power P2 of the hybrid powerautomobile, and the entire vehicle requirement power P2 of the hybridpower automobile is determined, where the entire vehicle requirementpower P2 may satisfy the following three cases.

In a first case, the entire vehicle requirement power P2 is less thanthe minimum output power Pmin corresponding to the optimal economicalarea of the engine; in a second case, the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor; and in a third case, the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor.

In an embodiment of the first case, when the entire vehicle requirementpower P2 is less than the minimum output power Pmin corresponding to theoptimal economical area of the engine, the charging power P3 of thepower battery is obtained according to the SOC value change rate of thepower battery, and whether the charging power P3 of the power battery isless than the difference between the minimum output power Pmin and theentire vehicle requirement power P2 is determined. If the charging powerP3 of the power battery is less than the difference between the minimumoutput power Pmin and the entire vehicle requirement power P2, theengine is controlled to perform power generation at the minimum outputpower Pmin to control the power generation power of the auxiliary motor;or if the charging power P3 of the power battery is greater than orequal to the difference between the minimum output power Pmin and theentire vehicle requirement power P2, an output power of the engine inthe preset optimal economical area is obtained according to a sum of thecharging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to control the power generationpower P1 of the auxiliary motor.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery and the charging power P3 of thepower battery may be pre-stored. Therefore, after an SOC value changerate of the power battery is obtained, a corresponding charging power P3of the power battery may be obtained by performing matching on the firstrelationship table. The SOC value change rate of the power battery andthe charging power P3 of the power battery satisfy a relationship shownin Table 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 battery 3Charging power P3 of the power B1 B2 B3 B4 B5 battery 3

It is learned from Table 1 that, when an obtained SOC value change rateis A1, an obtained corresponding charging power P3 of the power batteryis B1; when an obtained SOC value change rate is A2, an obtainedcorresponding charging power P3 of the power battery is B2; when anobtained SOC value change rate is A3, an obtained corresponding chargingpower P3 of the power battery is B3; when an obtained SOC value changerate is A4, an obtained corresponding charging power P3 of the powerbattery is B4; and when an obtained SOC value change rate is A5, anobtained corresponding charging power P3 of the power battery is B5.

Specifically, when performing power generation power control on theauxiliary motor, the entire vehicle drive power P11 and the electricappliance device power P21 are obtained in real time, so as to obtainthe entire vehicle requirement power P2 of the hybrid power automobile,and the entire vehicle requirement power P2 of the hybrid powerautomobile is determined. When the entire vehicle requirement power P2is less than the minimum output power Pmin corresponding to the optimaleconomical area of the engine, the charging power P3 of the powerbattery may be obtained according to the SOC value change rate of thepower battery, and whether the charging power P3 of the power battery isless than or equal to the difference between the minimum output powerPmin and the entire vehicle requirement power P2 is determined.

When the entire vehicle requirement power P2 is less than the minimumoutput power Pmin corresponding to the optimal economical area of theengine 1, if the charging power P3 of the power battery is less than thedifference between the minimum output power Pmin and the entire vehiclerequirement power P2, that is, P3<Pmin−P2, the engine is controlled toperform power generation at the minimum output power Pmin to control thepower generation power of the auxiliary motor 1. If the charging powerP3 of the power battery is greater than or equal to the differencebetween the minimum output power Pmin and the entire vehicle requirementpower P2, that is, P3≥Pmin−P2, the output power of the engine in thepreset optimal economical area is obtained according to the sum of thecharging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to control the power generationpower of the auxiliary motor.

Therefore, when the entire vehicle requirement power P2 is less than theminimum output power Pmin corresponding to the optimal economical areaof the engine, the power generation power of the engine is obtainedaccording to the relationship between the charging power P3 of the powerbattery and the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine and theentire vehicle requirement power P2, so that the engine runs in thepreset optimal economical area, and the engine performs only powergeneration but does not participate in drive, thereby reducing fuelconsumption of the engine, and reducing noise of the engine.

In an embodiment of the second case, when the entire vehicle requirementpower P2 is greater than or equal to the minimum output power Pmincorresponding to the optimal economical area of the engine and is lessthan or equal to the maximum allowed power generation power Pmax of theauxiliary motor, the charging power P3 of the power battery is obtainedaccording to the SOC value change rate of the power battery, an outputpower of the engine in the preset optimal economical area is obtainedaccording to a sum of the charging power P3 of the power battery and theentire vehicle requirement power P2, and the engine is controlled toperform power generation at the obtained output power to control thepower generation power P1 of the auxiliary motor.

Specifically, when the entire vehicle requirement power P2 is greaterthan or equal to the minimum output power Pmin corresponding to theoptimal economical area of the engine and is less than the maximumallowed power generation power Pmax of the auxiliary motor, the chargingpower P3 of the power battery is further obtained according to the SOCvalue change rate of the power battery when the engine is controlled tooperate in the preset optimal economical area, and the output power ofthe engine in the preset optimal economical area is obtained accordingto the sum of the charging power P3 of the power battery and the entirevehicle requirement power P2, where the obtained output power is equalto P3+P2. Then, the engine is controlled to perform power generation atthe obtained output power to control the power generation power P1 ofthe auxiliary motor, thereby increasing the SOC value of the powerbattery, and enabling the engine to operate in the preset optimaleconomical area.

Therefore, when the entire vehicle requirement power P2 is greater thanor equal to the minimum output power Pmin corresponding to the optimaleconomical area of the engine 1 and is less than the maximum allowedpower generation power Pmax of the auxiliary motor 5, the output powerof the engine 1 is obtained according to the sum of the charging powerP3 of the power battery 3 and the entire vehicle requirement power P2,so that the engine 1 runs in the preset optimal economical area, and theengine 1 performs only power generation but does not participate indrive, thereby reducing fuel consumption of the engine, and reducingnoise of the engine.

In an embodiment of the third case, when the entire vehicle requirementpower P2 is greater than the maximum allowed power generation power Pmaxof the auxiliary motor, the engine is further controlled to participatein drive to enable the engine to output power to wheels through theclutch.

Specifically, when the entire vehicle requirement power P2 is greaterthan the maximum allowed power generation power Pmax of the auxiliarymotor, that is, the entire vehicle requirement power P2 of the hybridpower automobile is greater than the power generation power P1 of theauxiliary motor, the engine is further controlled to output a driveforce to the wheels through the clutch to enable the engine toparticipate in drive. Therefore, the engine undertakes a part of a drivepower P, so as to reduce a requirement of the auxiliary motor on thepower generation power P1, so that the engine operates in the presetoptimal economical area.

Therefore, when the entire vehicle requirement power P2 is greater thanthe maximum allowed power generation power Pmax of the auxiliary motor,the power battery discharges outward to supply power to the power motor.In this case, the power motor is controlled to output power to thewheels of the hybrid power automobile, so that the engine operates inthe preset optimal economical area.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

As described above, as shown in FIG. 19, a power generation controlmethod for a hybrid power automobile of an embodiment of the presentinvention specifically includes the following steps:

S301: Obtain an SOC value M of a power battery and a speed V of thehybrid power automobile.

S302: Determine whether the speed V of the hybrid power automobile isless than a first preset speed V1.

If yes, step S303 is performed; or if not, step S304 is performed.

S303: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S307 is performed; or if not, step S306 is performed.

S304: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S305 is performed; or if not, step S306 is performed.

S305: Control an engine to participate in drive.

S306: Control the engine not to drive an auxiliary motor to performpower generation.

S307: Obtain an accelerator pedal depth D of the hybrid power automobileand an entire vehicle resistance F of the hybrid power automobile.

S308: Determine whether the accelerator pedal depth D is greater than afirst preset depth D1, whether the entire vehicle resistance F of thehybrid power automobile is greater than a first preset resistance F1, orwhether the SOC value M of the power battery is less than a preset limitvalue M2.

If yes, step S305 is performed; or if not, step S309 is performed.

S309: Obtain an entire vehicle requirement power P2 of the hybrid powerautomobile.

S310: Determine whether the entire vehicle requirement power P2 is lessthan or equal to a maximum allowed power generation power Pmax of theauxiliary motor.

If yes, step S311 is performed; or if not, step S305 is performed.

S311: Control the engine to drive the auxiliary motor to perform powergeneration, and the engine not to participate in drive.

S312: Determine whether the entire vehicle requirement power P2 is lessthan a minimum output power Pmin corresponding to an optimal economicalarea of the engine.

If yes, step S313 is performed; or if not, step S314 is performed.

S313: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery, and perform step S315.

S314: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery, and perform step S316.

S315: Determine whether the charging power P3 of the power battery isless than a difference between the minimum output power Pmin and theentire vehicle requirement power P2.

If yes, step S317 is performed; or if not, step S316 is performed.

S316: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery and the entire vehicle requirement power P2, and control theengine to perform power generation at the obtained output power.

S317: Control the engine to perform power generation at the minimumoutput power Pmin.

To sum up, according to the power generation control method for a hybridpower automobile of this embodiment of the present invention, the SOCvalue of the power battery and the speed of the hybrid power automobileare first obtained, and the auxiliary motor is controlled according tothe SOC value of the power battery and the speed of the hybrid powerautomobile to enter the power generation power adjustment mode, so thatthe engine runs in the preset optimal economical area, thereby reducingfuel consumption of the engine, improving running economy of the entirevehicle, reducing noise of the engine, implementing a plurality of drivemodes, maintaining low-speed electric balance and low-speed smoothnessof the entire vehicle, and improving performance of the entire vehicle.

Based on the hybrid power automobile and the power system thereof of theforegoing embodiments, an embodiment of the present invention furtherproposes yet another power generation control method for a hybrid powerautomobile.

FIG. 20 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention. As shown in FIG. 20, the power generation controlmethod for a hybrid power automobile includes the following steps:

S21: Obtain an SOC value of a power battery of the hybrid powerautomobile, a speed of the hybrid power automobile, and an SOC value ofa low-voltage storage battery of the hybrid power automobile.

It should be noted that, the SOC value of the power battery and the SOCvalue of the low-voltage storage battery may be collected through abattery management system of the hybrid power automobile, so as toobtain the SOC value of the power battery and the SOC value of thelow-voltage storage battery.

S22: Control an auxiliary motor of the hybrid power automobile accordingto the SOC value of the power battery and the speed of the hybrid powerautomobile to enter a power generation power adjustment mode, so that anengine of the hybrid power automobile runs in a preset optimaleconomical area, where the auxiliary motor performs power generationunder driving of the engine.

The power generation power adjustment mode is a mode of adjusting apower generation power of the engine, and in the power generation poweradjustment mode, the power generation power of the auxiliary motor maybe adjusted by controlling the engine to drive the auxiliary motor toperform power generation.

It should be further noted that, the preset optimal economical area ofthe engine may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine, a horizontalcoordinate indicates a rotational speed of the engine, and a curve a isa fuel economy curve of the engine. An area corresponding to the fueleconomy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine are locatedon an optimal fuel economy curve of the engine, the engine is located inthe optimal economical area. Therefore, in this embodiment of thepresent invention, the engine may be enabled, by controlling therotational speed and the output torque of the engine to fall on the fueleconomy curve of the engine, for example, the curve a, to run in thepreset optimal economical area.

S23: Adjust the power generation power of the auxiliary motor accordingto the SOC value of the low-voltage storage battery after the auxiliarymotor enters the power generation power adjustment mode.

Specifically, when the hybrid power automobile is travelling, the enginemay output power to wheels of the hybrid power automobile through aclutch, and the engine may further drive the auxiliary motor to performpower generation. Therefore, the output power of the engine mainlyincludes two parts, one part is output to the auxiliary motor, that is,the power for driving the auxiliary motor to perform power generation,and the other part is output to the wheels, that is, the power fordriving the wheels.

When the engine drives the auxiliary motor to perform power generation,the SOC value of the power battery and the speed of the hybrid powerautomobile may be first obtained, and then the auxiliary motor iscontrolled according to the SOC value of the power battery and the speedof the hybrid power automobile to enter the power generation poweradjustment mode, so that the engine operates in the preset optimaleconomical area. In the power generation power adjustment mode, thepower generation power of the auxiliary motor may be adjusted on thepremise of enabling the engine to operate in the preset optimaleconomical area. After the auxiliary motor enters the power generationpower adjustment mode, the power generation power of the auxiliary motoris further adjusted according to the SOC value of the low-voltagestorage battery.

Therefore, the engine is enabled to operate in the preset optimaleconomical area, and because the engine has lowest fuel consumption andhighest fuel economy in the preset optimal economical area, fuelconsumption of the engine may be reduced, noise of the engine may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel; and bycharging the low-voltage storage battery, power consumption requirementsof the low-voltage electric appliance device may be ensured, and whenthe auxiliary motor stops power generation and the power battery isfaulty or has an insufficient power level, low-voltage power supply ofthe entire vehicle may be implemented through the low-voltage storagebattery, and further it is ensured that the entire vehicle may travel inthe pure fuel mode, thereby improving travelling mileage of the entirevehicle.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than a preset limit value andis less than or equal to a first preset value, if the speed of thehybrid power automobile is less than a first preset speed, the auxiliarymotor is controlled to enter the power generation power adjustment mode.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery, for example, a value of determining to stopcharging, and may be preferably 30%. The preset limit value may be apreset lower limit value of the SOC value of the power battery, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power batteryis less than or equal to the preset limit value, the SOC value of thepower battery falls within the first power level range. In this case,the power battery performs only charging but does not performdischarging. When the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the SOC value of the power battery falls within the second power levelrange. In this case, the power battery has a charging requirement, thatis, the power battery may be actively charged. When the SOC value of thepower battery is greater than the first preset value, the SOC value ofthe power battery falls within the third power level range. In thiscase, the power battery may be not charged, that is, the power batteryis not actively charged.

Specifically, after the SOC value of the power battery and the speed ofthe hybrid power automobile are obtained, a range within which the SOCvalue of the power battery falls may be determined. If the SOC value ofthe power battery falls within the second power level range, and the SOCvalue of the power battery is greater than the preset limit value and isless than or equal to the first preset value, it indicates that thepower battery may be charged. In this case, whether the speed of thehybrid power automobile is less than the first preset speed is furtherdetermined. If the speed of the hybrid power automobile is less than thefirst preset speed, the auxiliary motor is controlled to enter the powergeneration power adjustment mode. In this case, the speed of the hybridpower automobile is relatively low, a needed drive force is relativelysmall, the power motor is sufficient to drive the hybrid powerautomobile to travel, and the engine may drive only the auxiliary motorto perform power generation, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Further, when the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,and the speed of the hybrid power automobile is less than the firstpreset speed, an entire vehicle requirement power of the hybrid powerautomobile is further obtained; and when the entire vehicle requirementpower is less than or equal to a maximum allowed power generation powerof the auxiliary motor, the auxiliary motor is controlled to enter thepower generation power adjustment mode.

To be specific, after it is determined that the SOC value of the powerbattery is greater than the preset limit value and is less than or equalto the first preset value, and the speed of the hybrid power automobileis less than the first preset speed, whether the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor may be further determine. If the entirevehicle requirement power is less than or equal to the maximum allowedpower generation power of the auxiliary motor, the auxiliary motor iscontrolled to enter the power generation power adjustment mode. In thiscase, a drive force needed by the entire vehicle is relatively small,the entire vehicle requirement power is relatively small, the powermotor is sufficient to drive the hybrid power automobile to travel, andthe engine may drive only the auxiliary motor to perform powergeneration, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, when the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the speed of the hybrid power automobile is less than the first presetspeed, and the entire vehicle requirement power is less than or equal tothe maximum allowed power generation power of the auxiliary motor, anaccelerator pedal depth of the hybrid power automobile and an entirevehicle resistance of the hybrid power automobile are further obtained;and when the accelerator pedal depth is less than or equal to a firstpreset depth and the entire vehicle resistance of the hybrid powerautomobile is less than or equal to a first preset resistance, theauxiliary motor is controlled to enter the power generation poweradjustment mode.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

To be specific, after it is determined that the SOC value of the powerbattery is greater than the preset limit value and is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed, and the entire vehicle requirementpower is less than or equal to the maximum allowed power generationpower of the auxiliary motor, whether the accelerator pedal depth isgreater than the first preset depth and whether the entire vehicleresistance of the hybrid power automobile is greater than the firstpreset resistance may be further determined. If the accelerator pedaldepth is less than or equal to the first preset depth and the entirevehicle resistance of the hybrid power automobile is less than or equalto the first preset resistance, the auxiliary motor is controlled toenter the power generation power adjustment mode. In this case, a driveforce needed by the entire vehicle is relatively small, the entirevehicle requirement power is relatively small, the accelerator pedaldepth is relatively small, the entire vehicle resistance is alsorelatively small, the power motor is sufficient to drive the hybridpower automobile to travel, and the engine may drive only the auxiliarymotor to perform power generation, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

Additionally, according to an embodiment of the present invention, whenthe SOC value of the power battery is less than the preset limit value,the speed of the hybrid power automobile is greater than or equal to thefirst preset speed, the entire vehicle requirement power is greater thanthe maximum allowed power generation power of the auxiliary motor, theaccelerator pedal depth is greater than the first preset depth, or theentire vehicle resistance of the hybrid power automobile is greater thanthe first preset resistance, the engine is controlled to participate indrive.

To be specific, when the SOC value of the power battery is less than thepreset limit value, the speed of the hybrid power automobile is greaterthan or equal to the first preset speed, the entire vehicle requirementpower is greater than the maximum allowed power generation power of theauxiliary motor, the accelerator pedal depth is greater than the firstpreset depth, or the entire vehicle resistance of the hybrid powerautomobile is greater than the first preset resistance, a control modulecontrols the engine to participate in drive. In this case, the powerbattery does not perform discharging again, the entire vehicle needs arelatively large drive force, the entire vehicle requirement power isrelatively large, the accelerator pedal depth is relatively large or theentire vehicle resistance is also relatively large, the power motor isinsufficient to drive the hybrid power automobile to travel, and theengine participates in drive to perform supplemental drive.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, when the entire vehicle requirement power is greaterthan the maximum allowed power generation power of the auxiliary motor,the engine is further controlled to participate in drive to enable theengine to output power to wheels of the hybrid power automobile throughthe clutch.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value, the engine is further controlled toparticipate in drive to enable the engine to output power to wheels ofthe hybrid power automobile through the clutch; when the SOC value ofthe power battery is less than or equal to the first preset value, thespeed of the hybrid power automobile is less than the first preset speedand the accelerator pedal depth is greater than the first preset depth,the engine is further controlled to participate in drive to enable theengine to output power to the wheels through the clutch; and when theSOC value of the power battery is less than or equal to the first presetvalue, the speed of the hybrid power automobile is less than the firstpreset speed and the entire vehicle resistance of the hybrid powerautomobile is greater than the first preset resistance, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch.

To be specific, the SOC value of the power battery, the acceleratorpedal depth of the hybrid power automobile, the speed, the entirevehicle resistance and the entire vehicle requirement power may beobtained in real time, and the SOC value of the power battery, theaccelerator pedal depth of the hybrid power automobile, the speed andthe entire vehicle resistance are determined:

First, when the SOC value of the power battery is less than the presetlimit value, because the power level of the power battery is excessivelylow, the power battery cannot provide sufficient electric energy, theengine and the power motor are controlled to simultaneously participatein drive, and the engine may be further controlled to drive theauxiliary motor to perform power generation to charge the power battery.In this case, the engine may be further controlled to drive theauxiliary motor to perform power generation, and by adjusting the powergeneration power of the auxiliary motor, the engine is enabled tooperate in the preset optimal economical area.

Second, when the SOC value of the power battery is less than or equal tothe first preset value, the speed of the hybrid power automobile is lessthan the first preset speed and the accelerator pedal depth is greaterthan the first preset depth, because the accelerator pedal depth isrelatively large, the control module controls the engine and the powermotor to simultaneously participate in drive. In this case, the enginemay be further controlled to drive the auxiliary motor to perform powergeneration, and by adjusting the power generation power of the auxiliarymotor, the engine is enabled to operate in the preset optimal economicalarea.

Third, when the SOC value of the power battery is less than or equal tothe first preset value, the speed of the hybrid power automobile is lessthan the first preset speed and the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance,because the entire vehicle resistance is relatively large, the engineand the power motor may be controlled to simultaneously participate indrive. In this case, the engine may be further controlled to drive theauxiliary motor to perform power generation, and by adjusting the powergeneration power of the auxiliary motor, the engine is enabled tooperate in the preset optimal economical area.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module is further configured to: when the SOCvalue of the power battery is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine to participate in drive to enablethe engine to output power to the wheels through the clutch.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module is furtherconfigured to: when the SOC value of the power battery is greater thanthe first preset value, control the engine not to drive the auxiliarymotor to perform power generation. In this case, the power battery hasan approximately full power level, and does not need to be charged, andthe engine does not drive the auxiliary motor to perform powergeneration. To be specific, when the power battery has an approximatelyfull power level, the engine does not drive the auxiliary motor toperform power generation, and therefore the auxiliary motor does notcharge the power battery.

Further, after the auxiliary motor enters the power generation poweradjustment mode, the power generation power of the auxiliary motor maybe adjusted. A process of adjusting the power generation power of thisembodiment of the present invention is specifically described below.

According to an embodiment of the present invention, after the auxiliarymotor enters the power generation power adjustment mode, the powergeneration power of the auxiliary motor is adjusted according to theentire vehicle requirement power of the hybrid power automobile, thecharging power of the power battery, the charging power of thelow-voltage storage battery, and the SOC value of the low-voltagestorage battery.

Specifically, a formula of adjusting the power generation power of theauxiliary motor according to the entire vehicle requirement power of thehybrid power automobile, the charging power of the power battery and thecharging power of the low-voltage storage battery is as follows:

P1=P2+P3+P4, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery, P4 is the charging power of the low-voltage storage battery,P11 is an entire vehicle drive power, and P21 is an electric appliancedevice power.

It should be noted that, electric appliance devices include a firstelectric appliance device and a second electric appliance device, thatis, the electric appliance device power P21 may include power needed bythe high-voltage electric appliance device and the low-voltage electricappliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor, and the entire vehicledrive power P11 may be obtained according to a presetaccelerator-torsional moment curve of the power motor and a rotationalspeed of the power motor, where the preset accelerator-torsional momentcurve may be determined during power matching of the hybrid powerautomobile. The electric appliance device power P21 may be obtained inreal time according to electric appliance devices running on the entirevehicle, for example, the electric appliance device power P21 iscalculated through DC consumption on a bus. The charging power P3 of thepower battery may be obtained according to the SOC value of the powerbattery, and the charging power P4 of the low-voltage storage battery isobtained according to the SOC value of the low-voltage storage battery.

Specifically, when the hybrid power automobile is travelling, thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery, the entire vehicle drive power P11 and theelectric appliance device power P21 may be obtained, and a sum of thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery, the entire vehicle drive power P11 and theelectric appliance device power P21 is used as the power generationpower P1 of the auxiliary motor. Therefore, the power generation powerof the auxiliary motor may be adjusted according to the calculated P1value. For example, the output torque and the rotational speed of theengine may be controlled according to the calculated P1 value, so as toadjust the power for the engine to drive the auxiliary motor to performpower generation.

Further, according to an embodiment of the present invention, theadjusting the power generation power of the auxiliary motor includes:obtaining an SOC value change rate of the power battery, and adjustingthe power generation power of the auxiliary motor according to arelationship between the entire vehicle requirement power P2 and aminimum output power corresponding to the optimal economical area of theengine, the SOC value change rate of the power battery, the SOC value ofthe low-voltage storage battery, and the SOC value change rate of thelow-voltage storage battery.

It should be understood that, the SOC value change rate of the powerbattery may be obtained according to the SOC value of the power battery,for example, the SOC value of the power battery is collected once ateach time interval t. In this way, a ratio of a difference between acurrent SOC value and a former SOC value of the power battery to thetime interval t may be used as the SOC value change rate of the powerbattery. Similarly, the SOC value change rate of the low-voltage storagebattery may be obtained according to the SOC value of the low-voltagestorage battery, for example, the SOC value of the low-voltage storagebattery is collected once at each time interval t. In this way, a ratioof a difference between a current SOC value and a former SOC value ofthe low-voltage storage battery to the time interval t may be used asthe SOC value change rate of the low-voltage storage battery.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power corresponding to theoptimal economical area of the engine is obtained. After the minimumoutput power corresponding to the optimal economical area of the engineis determined, the power generation power of the auxiliary motor may beadjusted according to the relationship between the entire vehiclerequirement power P2 and the minimum output power Pmin corresponding tothe optimal economical area of the engine, the SOC value change rate ofthe power battery, the SOC value of the low-voltage storage battery, andthe SOC value change rate of the low-voltage storage battery.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine may perform only power generation but does not participate indrive, and because the engine does not participate in drive, the clutchdoes not need to be used, thereby reducing abrasion or slip friction ofthe clutch, reducing an unsmooth feeling, and improving comfortableness,so as to maintain low-speed electric balance and low-speed smoothness ofthe entire vehicle and improve performance of the entire vehicle.

A specific control manner in which after the auxiliary motor 5 entersthe power generation power adjustment mode, the power generation powerof the auxiliary motor is adjusted according to the relationship betweenthe entire vehicle requirement power P2 and the minimum output powerPmin corresponding to the optimal economical area of the engine, the SOCvalue change rate of the power battery, the SOC value of the low-voltagestorage battery, and the SOC value change rate of the low-voltagestorage battery is further described below.

Specifically, when the SOC value of the low-voltage storage battery isgreater than a preset low power level threshold, the charging power ofthe power battery is obtained according to the SOC value change rate ofthe power battery, and whether the charging power of the power batteryis less than the difference between the minimum output powercorresponding to the optimal economical area of the engine and theentire vehicle requirement power is determined. If the charging power ofthe power battery is less than the difference between the minimum outputpower corresponding to the optimal economical area of the engine and theentire vehicle requirement power, the engine is controlled to performpower generation at the minimum output power to adjust the powergeneration power of the auxiliary motor; or if the charging power of thepower battery is greater than or equal to the difference between theminimum output power corresponding to the optimal economical area of theengine and the entire vehicle requirement power, the output power of theengine in the preset optimal economical area is obtained according tothe sum of the charging power of the power battery and the entirevehicle requirement power, and the engine is controlled to perform powergeneration at the obtained output power to adjust the power generationpower of the auxiliary motor.

Specifically, when the SOC value of the low-voltage storage battery isless than or equal to the preset low power level threshold, the SOCvalue change rate of the low-voltage storage battery and the SOC valuechange rate of the power battery are obtained, the charging power of thelow-voltage storage battery is obtained according to the SOC valuechange rate of the low-voltage storage battery, the charging power ofthe power battery is obtained according to the SOC value change rate ofthe power battery, and whether the sum of the charging power of thelow-voltage storage battery and the charging power of the power batteryis less than the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine and theentire vehicle requirement power is determined. If the sum of thecharging power of the low-voltage storage battery and the charging powerof the power battery is less than the difference between the minimumoutput power corresponding to the optimal economical area of the engineand the entire vehicle requirement power, the engine is controlled toperform power generation at the minimum output power to adjust the powergeneration power of the auxiliary motor; or if the sum of the chargingpower of the low-voltage storage battery and the charging power of thepower battery is greater than or equal to the difference between theminimum output power corresponding to the optimal economical area of theengine and the entire vehicle requirement power, the output power of theengine in the preset optimal economical area is obtained according tothe sum of the charging power of the power battery, the charging powerof the low-voltage storage battery and the entire vehicle requirementpower, and the engine is controlled to perform power generation at theobtained output power to adjust the power generation power of theauxiliary motor.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery and the charging power P3 of thepower battery may be pre-stored in the control module. Therefore, afteran SOC value change rate of the power battery is obtained, acorresponding charging power P3 of the power battery may be obtained byperforming matching on the first relationship table. For example, afirst relationship table between the SOC value change rate of the powerbattery and the charging power P3 of the power battery may be shown inTable 1.

TABLE 1 SOC value change rate of the power battery A1 A2 A3 A4 A5Charging power of the power battery B1 B2 B3 B4 B5

It can be learned from Table 1 that, when an SOC value change rate ofthe power battery is A1, a corresponding charging power P3 of the powerbattery that may be obtained is B1; when an SOC value change rate of thepower battery is A2, a corresponding charging power P3 of the powerbattery that may be obtained is B2; when an SOC value change rate of thepower battery is A3, a corresponding charging power P3 of the powerbattery that may be obtained is B3; when an SOC value change rate of thepower battery is A4, a corresponding charging power P3 of the powerbattery that may be obtained is B4; and when an SOC value change rate ofthe power battery is A5, a corresponding charging power P3 of the powerbattery that may be obtained is B5.

Similarly, a second relationship table between the SOC value change rateof the low-voltage storage battery and the charging power P4 of thelow-voltage storage battery may be pre-stored in the control module.Therefore, after an SOC value change rate of the low-voltage storagebattery is obtained, a corresponding charging power P4 of thelow-voltage storage battery may be obtained by performing matching onthe second relationship table. For example, a first relationship tablebetween the SOC value change rate of the low-voltage storage battery andthe charging power P4 of the low-voltage storage battery may be shown inTable 2.

TABLE 2 SOC value change rate of the A11 A12 A13 A14 A15 low-voltagestorage battery Charging power of the B11 B12 B13 B14 B15 low-voltagestorage battery

It can be learned from Table 2 that, when an SOC value change rate ofthe low-voltage storage battery is A11, a corresponding charging powerP4 of the low-voltage storage battery that may be obtained is B11; whenan SOC value change rate of the low-voltage storage battery is A12, acorresponding charging power P4 of the low-voltage storage battery thatmay be obtained is B12; when an SOC value change rate of the low-voltagestorage battery is A13, a corresponding charging power P4 of thelow-voltage storage battery that may be obtained is B13; when an SOCvalue change rate of the low-voltage storage battery is A14, acorresponding charging power P4 of the low-voltage storage battery thatmay be obtained is B14; and when an SOC value change rate of thelow-voltage storage battery is A15, a corresponding charging power P4 ofthe low-voltage storage battery that may be obtained is B15.

Specifically, after the auxiliary motor 5 enters the power generationpower adjustment mode, the SOC value of the low-voltage storage battery,the SOC value of the power battery, and the entire vehicle requirementpower P2 (the sum of the entire vehicle drive power P11 and the electricappliance device power P21) may be obtained, and then whether the SOCvalue of the low-voltage storage battery is greater than the preset lowpower level threshold is determined.

If the SOC value of the low-voltage storage battery is greater than thepreset low power level threshold, the SOC value change rate of the powerbattery is obtained, and the charging power P3 of the power batterycorresponding to the SOC value change rate of the power battery isqueried for, so as to select an appropriate charging power P3 to enablethe SOC value of the power battery to increase; and whether the chargingpower P3 of the power battery is less than the difference between theminimum output power Pmin corresponding to the optimal economical areaof the engine and the entire vehicle requirement power P2 is furtherdetermined. If yes, that is, P3<Pmin−P2, the engine is controlled toperform power generation at the minimum output power Pmin to adjust thepower generation power of the auxiliary motor, that is, the engine iscontrolled to run at the minimum output power Pmin corresponding to theoptimal economical area, and to charge the power battery at a powerequal to the minimum output power Pmin corresponding to the optimaleconomical area minus the entire vehicle requirement power P2, that is,Pmin−P2; or if not, that is, P3≥Pmin−P2, the output power of the enginein the preset optimal economical area is obtained according to the sumof the charging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to adjust the power generationpower of the auxiliary motor. To be specific, a corresponding outputpower is searched for in the preset optimal economical area of theengine, where the obtained output power may be the sum of the chargingpower P3 of the power battery and the entire vehicle requirement powerP2, that is, (P2+P3 or P11+P21+P3), and the engine is controlled toperform power generation at the obtained output power.

If the SOC value of the low-voltage storage battery is less than orequal to the preset low power level threshold, the SOC value change rateof the power battery is obtained, and the charging power P3 of the powerbattery corresponding to the SOC value change rate of the power batteryis queried for, so as to select an appropriate charging power P3 toenable the SOC value of the power battery to increase; the SOC valuechange rate of the low-voltage storage battery is obtained, and thecharging power P4 of the low-voltage storage battery corresponding tothe SOC value change rate of the low-voltage storage battery is queriedfor, to select an appropriate charging power P4 to enable the SOC valueof the low-voltage storage battery to increase; and whether the sum ofthe charging power P4 of the low-voltage storage battery and thecharging power P3 of the power battery is less than the differencebetween the minimum output power Pmin corresponding to the optimaleconomical area of the engine and the entire vehicle requirement powerP2 is further determined. If yes, that is, P3+P4<Pmin−P2, the engine iscontrolled to perform power generation at the minimum output power Pminto adjust the power generation power of the auxiliary motor, that is,the engine is controlled to run at the minimum output power Pmincorresponding to the optimal economical area, and to charge the powerbattery and the low-voltage storage battery at a power equal to theminimum output power Pmin corresponding to the optimal economical areaminus the entire vehicle requirement power P2, that is, Pmin−P2; or ifnot, that is, P3+P4≥Pmin−P2, the output power of the engine in thepreset optimal economical area is obtained according to the sum of thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery and the entire vehicle requirement power P2,and the engine is controlled to perform power generation at the obtainedoutput power to adjust the power generation power of the auxiliarymotor. To be specific, a corresponding output power is searched for inthe preset optimal economical area of the engine, where the obtainedoutput power may be the sum of the charging power P3 of the powerbattery, the charging power P4 of the low-voltage storage battery andthe entire vehicle requirement power P2, that is, (P2+P3+P4 orP11+P21+P3+P4), and the engine is controlled to perform power generationat the obtained output power.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

As described above, as shown in FIG. 21, a power generation controlmethod for a hybrid power automobile of an embodiment of the presentinvention includes the following steps:

S601: Obtain an SOC value M of a power battery and a speed V of thehybrid power automobile.

S602: Determine whether the speed V of the hybrid power automobile isless than a first preset speed V1.

If yes, step S603 is performed; or if not, step S604 is performed.

S603: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S607 is performed; or if not, step S606 is performed.

S604: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S605 is performed; or if not, step S606 is performed.

S605: Control an engine to participate in drive.

S606: Control the engine not to drive an auxiliary motor to performpower generation.

S607: Obtain an accelerator pedal depth D of the hybrid power automobileand an entire vehicle resistance F of the hybrid power automobile.

S608: Determine whether the accelerator pedal depth D is greater than afirst preset depth D1, whether the entire vehicle resistance F of thehybrid power automobile is greater than a first preset resistance F1, orwhether the SOC value M of the power battery is less than a preset limitvalue M2.

If yes, step S605 is performed; or if not, step S609 is performed.

S609: Obtain an entire vehicle requirement power P2 of the hybrid powerautomobile.

S610: Determine whether the entire vehicle requirement power P2 is lessthan or equal to a maximum allowed power generation power Pmax of theauxiliary motor.

If yes, step S611 is performed; or if not, step S605 is performed.

S611: Control the engine to drive the auxiliary motor to perform powergeneration, and the engine not to participate in drive. In this case,the auxiliary motor is controlled to enter a power generation poweradjustment mode.

S612: Determine whether an SOC value of a low-voltage storage battery isless than or equal to a preset low power level threshold.

If yes, step S617 is performed; or if not, step S613 is performed.

S613: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery.

S614: Determine whether the charging power P3 of the power battery isless than a difference between a minimum output power Pmin correspondingto an optimal economical area of the engine and the entire vehiclerequirement power P2.

If yes, step S615 is performed; or if not, step S616 is performed.

S615: Control the engine to perform power generation at the minimumoutput power Pmin to adjust a power generation power of the auxiliarymotor.

S616: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery and the entire vehicle requirement power P2, and control theengine to perform power generation at the obtained output power toadjust a power generation power of the auxiliary motor.

S617: Obtain a charging power P4 of the low-voltage storage batteryaccording to an SOC value change rate of the low-voltage storagebattery.

S618: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery.

S619: Determine whether a sum of the charging power P4 of thelow-voltage storage battery and the charging power P3 of the powerbattery is less than a difference between a minimum output power Pmincorresponding to an optimal economical area of the engine and the entirevehicle requirement power P2.

If yes, step S620 is performed; or if not, step S621 is performed.

S620: Control the engine to perform power generation at the minimumoutput power Pmin to adjust a power generation power of the auxiliarymotor.

S621: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery, the charging power P4 of the low-voltage storage battery andthe entire vehicle requirement power P2, and control the engine toperform power generation at the obtained output power to adjust a powergeneration power of the auxiliary motor.

To sum up, according to the power generation control method for a hybridpower automobile proposed in this embodiment of the present invention,the SOC value of the power battery, the SOC value of the low-voltagestorage battery and the speed of the hybrid power automobile areobtained, and the auxiliary motor is controlled according to the SOCvalue of the power battery and the speed of the hybrid power automobileto enter the power generation power adjustment mode, so that the engineruns in the preset optimal economical area. After the auxiliary motorenters the power generation power adjustment mode, the power generationpower of the auxiliary motor is further adjusted according to the SOCvalue of the low-voltage storage battery. Therefore, the engine isenabled not to participate in drive at a low speed, and therefore theclutch is not used, thereby reducing abrasion or slip friction of theclutch, reducing an unsmooth feeling, and improving comfortableness; andat a low speed, the engine is enabled to operate in an economical area,to perform only power generation but does not perform drive, therebyreducing fuel consumption, reducing noise of the engine, maintaininglow-speed electric balance and low-speed smoothness of the entirevehicle, and improving performance of the entire vehicle.

Based on the hybrid power automobile and the power system thereof of theforegoing embodiments, an embodiment of the present invention furtherproposes yet another power generation control method for a hybrid powerautomobile.

FIG. 22 is a flowchart of a power generation control method for a powersystem of a hybrid power automobile according to an embodiment of thepresent invention. As shown in FIG. 22, the power generation controlmethod for a hybrid power automobile includes the following steps:

S31: Obtain an SOC value of a power battery of the hybrid powerautomobile, a speed of the hybrid power automobile, and an SOC value ofa low-voltage storage battery of the hybrid power automobile.

It should be noted that, the SOC value of the power battery and the SOCvalue of the low-voltage storage battery may be collected through abattery management system of the hybrid power automobile, so as toobtain the SOC value of the power battery and the SOC value of thelow-voltage storage battery.

S32: Control a power generation power of an auxiliary motor of thehybrid power automobile according to the SOC value of the power battery,the SOC value of the low-voltage storage battery and the speed of thehybrid power automobile.

S33: Obtain a power generation power of an engine of the hybrid powerautomobile according to the power generation power of the auxiliarymotor, so as to control the engine to run in a preset optimal economicalarea, where the auxiliary motor performs power generation under drivingof the engine.

It should be further noted that, the preset optimal economical area ofthe engine may be determined with reference to a diagram of an engineuniversal characteristic curve. FIG. 7 shows an example of the diagramof the engine universal characteristic curve, where a verticalcoordinate indicates an output torque of the engine, a horizontalcoordinate indicates a rotational speed of the engine, and a curve a isa fuel economy curve of the engine. An area corresponding to the fueleconomy curve is the optimal economical area of the engine. To bespecific, when a torsional moment and a torque of the engine are locatedon an optimal fuel economy curve of the engine, the engine is located inthe optimal economical area. Therefore, in this embodiment of thepresent invention, the engine may be enabled, by controlling therotational speed and the output torque of the engine to fall on the fueleconomy curve of the engine, for example, the curve a, to run in thepreset optimal economical area.

Specifically, when the hybrid power automobile is travelling, the enginemay output power to wheels of the hybrid power automobile through aclutch, and the engine may further drive the auxiliary motor to performpower generation. Therefore, the output power of the engine mainlyincludes two parts, one part is output to the auxiliary motor, that is,the power generation power for driving the auxiliary motor to performpower generation, and the other part is output to the wheels, that is,the drive power for driving the wheels.

When the engine drives the auxiliary motor to perform power generation,the SOC value of the power battery, the SOC value of the low-voltagestorage battery and the speed of the hybrid power automobile may befirst obtained, the power generation power of the auxiliary motor isthen controlled according to the SOC value of the power battery, the SOCvalue of the low-voltage storage battery and the speed of the hybridpower automobile, and the power generation power of the engine isfurther obtained according to the power generation power of theauxiliary motor, so as to control the engine to run in the presetoptimal economical area. In other words, a control module may controlthe power generation power of the auxiliary motor on the premise ofenabling the engine to operate in the preset optimal economical area.

Therefore, the engine is enabled to operate in the preset optimaleconomical area, and because the engine has lowest fuel consumption andhighest fuel economy in the preset optimal economical area, fuelconsumption of the engine may be reduced, noise of the engine may bereduced, and running economy of the entire vehicle may be improved.Moreover, because the auxiliary motor has relatively high powergeneration power and power generation efficiency at a low speed, powerconsumption requirements of low-speed travelling may be satisfied, andlow-speed electric balance of the entire vehicle and low-speedsmoothness of the entire vehicle may be maintained, to improve powerperformance of the entire vehicle. By charging the power battery, powerconsumption requirements of the power motor and the high-voltageelectric appliance device may be ensured, and further it is ensured thatthe power motor drives the entire vehicle to normally travel; and bycharging the low-voltage storage battery, power consumption requirementsof the low-voltage electric appliance device may be ensured, and whenthe auxiliary motor stops power generation and the power battery isfaulty or has an insufficient power level, low-voltage power supply ofthe entire vehicle may be implemented through the low-voltage storagebattery, and further it is ensured that the entire vehicle may travel inthe pure fuel mode, thereby improving travelling mileage of the entirevehicle.

Further, according to an embodiment of the present invention, when theSOC value of the power battery is greater than a preset limit value andis less than or equal to a first preset value, if the speed of thehybrid power automobile is less than a first preset speed, the powergeneration power of the auxiliary motor is controlled.

The first preset value may be a preset upper limit value of the SOCvalue of the power battery, for example, a value of determining to stopcharging, and may be preferably 30%. The preset limit value may be apreset lower limit value of the SOC value of the power battery, forexample, a value of determining to stop discharging, and may bepreferably 10%. SOC values of the power battery may be divided intothree ranges according to the first preset value and the preset limitvalue, that is, a first power level range, a second power level range,and a third power level range. When the SOC value of the power batteryis less than or equal to the preset limit value, the SOC value of thepower battery falls within the first power level range. In this case,the power battery performs only charging but does not performdischarging. When the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the SOC value of the power battery falls within the second power levelrange. In this case, the power battery has a charging requirement, thatis, the power battery may be actively charged. When the SOC value of thepower battery is greater than the first preset value, the SOC value ofthe power battery falls within the third power level range. In thiscase, the power battery may be not charged, that is, the power batteryis not actively charged.

Specifically, after the SOC value of the power battery and the speed ofthe hybrid power automobile are obtained, a range within which the SOCvalue of the power battery falls may be determined. If the SOC value ofthe power battery falls within the second power level range, and the SOCvalue of the power battery is greater than the preset limit value and isless than or equal to the first preset value, it indicates that thepower battery may be charged. In this case, whether the speed of thehybrid power automobile is less than the first preset speed is furtherdetermined. If the speed of the hybrid power automobile is less than thefirst preset speed, the power generation power of the auxiliary motor iscontrolled. In this case, the speed of the hybrid power automobile isrelatively low, a needed drive force is relatively small, the powermotor is sufficient to drive the hybrid power automobile to travel, andthe engine may drive only the auxiliary motor to perform powergeneration, but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness.

Further, when the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,and the speed of the hybrid power automobile is less than the firstpreset speed, an entire vehicle requirement power of the hybrid powerautomobile is further obtained; and when the entire vehicle requirementpower is less than or equal to a maximum allowed power generation powerof the auxiliary motor, the power generation power of the auxiliarymotor is controlled.

To be specific, after it is determined that the SOC value of the powerbattery is greater than the preset limit value and is less than or equalto the first preset value, and the speed of the hybrid power automobileis less than the first preset speed, whether the entire vehiclerequirement power is greater than the maximum allowed power generationpower of the auxiliary motor may be further determine. If the entirevehicle requirement power is less than or equal to the maximum allowedpower generation power of the auxiliary motor, the power generationpower of the auxiliary motor is controlled. In this case, a drive forceneeded by the entire vehicle is relatively small, the entire vehiclerequirement power is relatively small, the power motor is sufficient todrive the hybrid power automobile to travel, and the engine may driveonly the auxiliary motor to perform power generation, but does notparticipate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

Furthermore, when the SOC value of the power battery is greater than thepreset limit value and is less than or equal to the first preset value,the speed of the hybrid power automobile is less than the first presetspeed, and the entire vehicle requirement power is less than or equal tothe maximum allowed power generation power of the auxiliary motor, anaccelerator pedal depth of the hybrid power automobile and an entirevehicle resistance of the hybrid power automobile are further obtained;and when the accelerator pedal depth is less than or equal to a firstpreset depth and the entire vehicle resistance of the hybrid powerautomobile is less than or equal to a first preset resistance, the powergeneration power of the auxiliary motor is controlled.

It should be noted that, the entire vehicle resistance of the hybridpower automobile may be travelling resistances of the hybrid powerautomobile, for example, a rolling resistance, an acceleratingresistance, a grade resistance, and an air resistance.

To be specific, after it is determined that the SOC value of the powerbattery is greater than the preset limit value and is less than or equalto the first preset value, the speed of the hybrid power automobile isless than the first preset speed, and the entire vehicle requirementpower is less than or equal to the maximum allowed power generationpower of the auxiliary motor, whether the accelerator pedal depth isgreater than the first preset depth and whether the entire vehicleresistance of the hybrid power automobile is greater than the firstpreset resistance may be further determined. If the accelerator pedaldepth is less than or equal to the first preset depth and the entirevehicle resistance of the hybrid power automobile is less than or equalto the first preset resistance, the power generation power of theauxiliary motor is controlled. In this case, a drive force needed by theentire vehicle is relatively small, the entire vehicle requirement poweris relatively small, the accelerator pedal depth is relatively small,the entire vehicle resistance is also relatively small, the power motoris sufficient to drive the hybrid power automobile to travel, and theengine may drive only the auxiliary motor to perform power generation,but does not participate in drive.

Therefore, at a low speed, the engine performs only power generation butdoes not participate in drive, and because the engine does notparticipate in drive, the clutch does not need to be used, therebyreducing abrasion or slip friction of the clutch, reducing an unsmoothfeeling, and improving comfortableness.

As described above, when the hybrid power automobile is travelling at alow speed, the engine may perform only power generation but does notparticipate in drive, and because the engine does not participate indrive, the clutch does not need to be used, thereby reducing abrasion orslip friction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness. Moreover, the low speed enables the engine to operatein an economical area, and because the engine has lowest fuelconsumption and highest fuel economy in the preset optimal economicalarea, thereby reducing fuel consumption, reducing noise of the engine,and improving running economy of the entire vehicle, so as to maintainlow-speed electric balance and low-speed smoothness of the entirevehicle and improve performance of the entire vehicle.

According to a specific embodiment of the present invention, when theengine is controlled to individually drive the auxiliary motor toperform power generation and the power motor is controlled to output adrive force alone, the power generation power of the engine is obtainedaccording to the following formula:

P0=P1/η/ζ

where P0 is the power generation power of the engine, P1 is the powergeneration power of the auxiliary motor, η is belt transmissionefficiency, and ζ is efficiency of the auxiliary motor.

To be specific, if the engine may perform only power generation but doesnot participate in drive, the control module may calculate the powergeneration power P0 of the engine according to the power generationpower of the auxiliary motor, the belt transmission efficiency η and theefficiency ζ of the auxiliary motor, and control the engine to drive theauxiliary motor at the obtained power generation power P0 to performpower generation, so as to control the power generation power of theauxiliary motor.

Additionally, according to an embodiment of the present invention, whenthe SOC value of the power battery is less than the preset limit value,the speed of the hybrid power automobile is greater than or equal to thefirst preset speed, the entire vehicle requirement power is greater thanthe maximum allowed power generation power of the auxiliary motor, theaccelerator pedal depth is greater than the first preset depth, or theentire vehicle resistance of the hybrid power automobile is greater thanthe first preset resistance, the engine is controlled to participate indrive.

To be specific, when the SOC value of the power battery is less than thepreset limit value, the speed of the hybrid power automobile is greaterthan or equal to the first preset speed, the entire vehicle requirementpower is greater than the maximum allowed power generation power of theauxiliary motor, the accelerator pedal depth is greater than the firstpreset depth, or the entire vehicle resistance of the hybrid powerautomobile is greater than the first preset resistance, the controlmodule controls the engine to participate in drive. In this case, thepower battery does not perform discharging again, the entire vehicleneeds a relatively large drive force, the entire vehicle requirementpower is relatively large, the accelerator pedal depth is relativelylarge or the entire vehicle resistance is also relatively large, thepower motor is insufficient to drive the hybrid power automobile totravel, and the engine participates in drive to perform supplementaldrive.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

More specifically, when the entire vehicle requirement power is greaterthan the maximum allowed power generation power of the auxiliary motor,the engine is further controlled to participate in drive to enable theengine to output power to wheels of the hybrid power automobile throughthe clutch.

Moreover, when the SOC value of the power battery is less than or equalto the preset limit value, the engine is further controlled toparticipate in drive to enable the engine to output power to wheels ofthe hybrid power automobile through the clutch; when the SOC value ofthe power battery is less than or equal to the first preset value, thespeed of the hybrid power automobile is less than the first preset speedand the accelerator pedal depth is greater than the first preset depth,the engine is further controlled to participate in drive to enable theengine to output power to the wheels through the clutch; and when theSOC value of the power battery is less than or equal to the first presetvalue, the speed of the hybrid power automobile is less than the firstpreset speed and the entire vehicle resistance of the hybrid powerautomobile is greater than the first preset resistance, the engine isfurther controlled to participate in drive to enable the engine tooutput power to the wheels through the clutch.

To be specific, the SOC value of the power battery, the acceleratorpedal depth of the hybrid power automobile, the speed, the entirevehicle resistance and the entire vehicle requirement power may beobtained in real time, and the SOC value of the power battery, theaccelerator pedal depth of the hybrid power automobile, the speed andthe entire vehicle resistance are determined:

First, when the SOC value of the power battery is less than the presetlimit value, because the power level of the power battery is excessivelylow, and the power battery cannot provide sufficient electric energy,the engine and the power motor are controlled to simultaneouslyparticipate in drive. In this case, the engine may be further controlledto drive the auxiliary motor to perform power generation, and bycontrolling the power generation power of the engine, the engine isenabled to operate in the preset optimal economical area.

Second, when the SOC value of the power battery is less than or equal tothe first preset value, the speed of the hybrid power automobile is lessthan the first preset speed and the accelerator pedal depth is greaterthan the first preset depth, because the accelerator pedal depth isrelatively large, the control module controls the engine and the powermotor to simultaneously participate in drive. In this case, the enginemay be further controlled to drive the auxiliary motor to perform powergeneration, and by controlling the power generation power of the engine,the engine is enabled to operate in the preset optimal economical area.

Third, when the SOC value of the power battery is less than or equal tothe first preset value, the speed of the hybrid power automobile is lessthan the first preset speed and the entire vehicle resistance of thehybrid power automobile is greater than the first preset resistance,because the entire vehicle resistance is relatively large, the controlmodule controls the engine and the power motor to simultaneouslyparticipate in drive. In this case, the engine may be further controlledto drive the auxiliary motor to perform power generation, and bycontrolling the power generation power of the engine, the engine isenabled to operate in the preset optimal economical area.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.Moreover, the engine may be controlled to operate in an economical area,and because the engine 1 has lowest fuel consumption and highest fueleconomy in the preset optimal economical area, fuel consumption may bereduced, noise of the engine may be reduced, and economic performance ofthe entire vehicle may be improved.

Moreover, the control module is further configured to: when the SOCvalue of the power battery is less than or equal to the preset limitvalue, and the speed of the hybrid power automobile is greater than thefirst preset speed, control the engine to participate in drive to enablethe engine to output power to the wheels through the clutch.

Therefore, the engine may participate in drive when the drive forceoutput by the power motor is insufficient, thereby ensuring normaltravelling of the entire vehicle, improving power performance of theentire vehicle, and improving travelling mileage of the entire vehicle.

Certainly, it should be understood that, the control module is furtherconfigured to: when the SOC value of the power battery is greater thanthe first preset value, control the engine not to drive the auxiliarymotor to perform power generation. In this case, the power battery hasan approximately full power level, and does not need to be charged, andthe engine does not drive the auxiliary motor to perform powergeneration. To be specific, when the power battery has an approximatelyfull power level, the engine does not drive the auxiliary motor toperform power generation, and therefore the auxiliary motor does notcharge the power battery.

Further, when the engine drives only the auxiliary motor to performpower generation but does not participate in drive, the power generationpower of the auxiliary motor may be adjusted. A process of controllingthe power generation power of this embodiment of the present inventionis specifically described below.

According to an embodiment of the present invention, the powergeneration power of the auxiliary motor is further controlled accordingto the entire vehicle requirement power of the hybrid power automobile,the charging power of the power battery and the charging power of thelow-voltage storage battery.

Specifically, a formula of controlling the power generation power of theauxiliary motor according to the entire vehicle requirement power of thehybrid power automobile, the charging power of the power battery and thecharging power of the low-voltage storage battery is as follows:

P1=P2+P3+P4, where P2=P11+P21.

P1 is the power generation power of the auxiliary motor, P2 is theentire vehicle requirement power, P3 is the charging power of the powerbattery, P4 is the charging power of the low-voltage storage battery,P11 is an entire vehicle drive power, and P21 is an electric appliancedevice power.

It should be noted that, electric appliance devices include a firstelectric appliance device and a second electric appliance device, thatis, the electric appliance device power P21 may include power needed bythe high-voltage electric appliance device and the low-voltage electricappliance device.

It should be further noted that, the entire vehicle drive power P11 mayinclude the output power of the power motor, and the entire vehicledrive power P11 may be obtained according to a presetaccelerator-torsional moment curve of the power motor and a rotationalspeed of the power motor, where the preset accelerator-torsional momentcurve may be determined during power matching of the hybrid powerautomobile. The electric appliance device power P21 may be obtained inreal time according to electric appliance devices running on the entirevehicle, for example, the electric appliance device power P21 iscalculated through DC consumption on a bus. The charging power P3 of thepower battery may be obtained according to the SOC value of the powerbattery, and the charging power P4 of the low-voltage storage battery isobtained according to the SOC value of the low-voltage storage battery.

Specifically, when the hybrid power automobile is travelling, thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery, the entire vehicle drive power P11 and theelectric appliance device power P21 may be obtained, and a sum of thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery, the entire vehicle drive power P11 and theelectric appliance device power P21 is used as the power generationpower P1 of the auxiliary motor. Therefore, the power generation powerof the auxiliary motor may be controlled according to the calculated P1value. For example, the output torque and the rotational speed of theengine may be controlled according to the calculated P1 value, so as tocontrol the power for the engine to drive the auxiliary motor to performpower generation.

Further, according to an embodiment of the present invention, thecontrolling the power generation power of the auxiliary motor includes:obtaining an SOC value change rate of the power battery, and controllingthe power generation power of the auxiliary motor according to arelationship between the entire vehicle requirement power P2 and aminimum output power corresponding to the optimal economical area of theengine, the SOC value change rate of the power battery, the SOC value ofthe low-voltage storage battery, and the SOC value change rate of thelow-voltage storage battery.

It should be understood that, the SOC value change rate of the powerbattery may be obtained according to the SOC value of the power battery,for example, the SOC value of the power battery is collected once ateach time interval t. In this way, a ratio of a difference between acurrent SOC value and a former SOC value of the power battery to thetime interval t may be used as the SOC value change rate of the powerbattery. Similarly, the SOC value change rate of the low-voltage storagebattery may be obtained according to the SOC value of the low-voltagestorage battery, for example, the SOC value of the low-voltage storagebattery is collected once at each time interval t. In this way, a ratioof a difference between a current SOC value and a former SOC value ofthe low-voltage storage battery to the time interval t may be used asthe SOC value change rate of the low-voltage storage battery.

Specifically, the optimal economical area of the engine may bedetermined according to the engine universal characteristic curve shownin FIG. 7, and then the minimum output power corresponding to theoptimal economical area of the engine is obtained. After the minimumoutput power corresponding to the optimal economical area of the engineis determined, the power generation power of the auxiliary motor may becontrolled according to the relationship between the entire vehiclerequirement power P2 and the minimum output power Pmin corresponding tothe optimal economical area of the engine, the SOC value change rate ofthe power battery, the SOC value of the low-voltage storage battery, andthe SOC value change rate of the low-voltage storage battery.

Therefore, when the hybrid power automobile is travelling at a lowspeed, the engine is enabled to operate in an economical area, therebyreducing fuel consumption, reducing noise of the engine, and improvingeconomic performance of the entire vehicle. Moreover, at a low speed,the engine may perform only power generation but does not participate indrive, and because the engine does not participate in drive, the clutchdoes not need to be used, thereby reducing abrasion or slip friction ofthe clutch, reducing an unsmooth feeling, and improving comfortableness,so as to maintain low-speed electric balance and low-speed smoothness ofthe entire vehicle and improve performance of the entire vehicle.

A specific control manner in which when the engine drives only theauxiliary motor to perform power generation but does not participate indrive, the power generation power of the auxiliary motor is controlledaccording to the relationship between the entire vehicle requirementpower P2 and the minimum output power Pmin corresponding to the optimaleconomical area of the engine, the SOC value change rate of the powerbattery, the SOC value of the low-voltage storage battery, and the SOCvalue change rate of the low-voltage storage battery is furtherdescribed below.

Specifically, when the SOC value of the low-voltage storage battery isgreater than a preset low power level threshold, the charging power ofthe power battery is obtained according to the SOC value change rate ofthe power battery, and whether the charging power of the power batteryis less than the difference between the minimum output powercorresponding to the optimal economical area of the engine and theentire vehicle requirement power is determined. If the charging power ofthe power battery is less than the difference between the minimum outputpower corresponding to the optimal economical area of the engine and theentire vehicle requirement power, the engine is controlled to performpower generation at the minimum output power to control the powergeneration power of the auxiliary motor; or if the charging power of thepower battery is greater than or equal to the difference between theminimum output power corresponding to the optimal economical area of theengine and the entire vehicle requirement power, the output power of theengine in the preset optimal economical area is obtained according tothe sum of the charging power of the power battery and the entirevehicle requirement power, and the engine is controlled to perform powergeneration at the obtained output power to control the power generationpower of the auxiliary motor.

Specifically, when the SOC value of the low-voltage storage battery isless than or equal to the preset low power level threshold, the SOCvalue change rate of the low-voltage storage battery and the SOC valuechange rate of the power battery are obtained, the charging power of thelow-voltage storage battery is obtained according to the SOC valuechange rate of the low-voltage storage battery, the charging power ofthe power battery is obtained according to the SOC value change rate ofthe power battery, and whether the sum of the charging power of thelow-voltage storage battery and the charging power of the power batteryis less than the difference between the minimum output power Pmincorresponding to the optimal economical area of the engine and theentire vehicle requirement power is determined. If the sum of thecharging power of the low-voltage storage battery and the charging powerof the power battery is less than the difference between the minimumoutput power corresponding to the optimal economical area of the engineand the entire vehicle requirement power, the engine is controlled toperform power generation at the minimum output power to control thepower generation power of the auxiliary motor; or if the sum of thecharging power of the low-voltage storage battery and the charging powerof the power battery is greater than or equal to the difference betweenthe minimum output power corresponding to the optimal economical area ofthe engine and the entire vehicle requirement power, the output power ofthe engine in the preset optimal economical area is obtained accordingto the sum of the charging power of the power battery, the chargingpower of the low-voltage storage battery and the entire vehiclerequirement power, and the engine is controlled to perform powergeneration at the obtained output power to control the power generationpower of the auxiliary motor.

It should be noted that, a first relationship table between the SOCvalue change rate of the power battery and the charging power P3 of thepower battery may be pre-stored in the control module. Therefore, afteran SOC value change rate of the power battery is obtained, acorresponding charging power P3 of the power battery may be obtained byperforming matching on the first relationship table. For example, afirst relationship table between the SOC value change rate of the powerbattery and the charging power P3 of the power battery may be shown inTable 1.

TABLE 1 SOC value change rate of the power A1 A2 A3 A4 A5 batteryCharging power of the power battery B1 B2 B3 B4 B5

It can be learned from Table 1 that, when an SOC value change rate ofthe power battery is A1, a corresponding charging power P3 of the powerbattery that may be obtained is B1; when an SOC value change rate of thepower battery is A2, a corresponding charging power P3 of the powerbattery that may be obtained is B2; when an SOC value change rate of thepower battery is A3, a corresponding charging power P3 of the powerbattery that may be obtained is B3; when an SOC value change rate of thepower battery is A4, a corresponding charging power P3 of the powerbattery that may be obtained is B4; and when an SOC value change rate ofthe power battery is A5, a corresponding charging power P3 of the powerbattery that may be obtained is B5.

Similarly, a second relationship table between the SOC value change rateof the low-voltage storage battery and the charging power P4 of thelow-voltage storage battery may be pre-stored in the control module.Therefore, after an SOC value change rate of the low-voltage storagebattery is obtained, a corresponding charging power P4 of thelow-voltage storage battery may be obtained by performing matching onthe second relationship table. For example, a first relationship tablebetween the SOC value change rate of the low-voltage storage battery andthe charging power P4 of the low-voltage storage battery may be shown inTable 2.

TABLE 2 SOC value change rate of the A11 A12 A13 A14 A15 low-voltagestorage battery Charging power of the B11 B12 B13 B14 B15 low-voltagestorage battery

It can be learned from Table 2 that, when an SOC value change rate ofthe low-voltage storage battery is A11, a corresponding charging powerP4 of the low-voltage storage battery that may be obtained is B11; whenan SOC value change rate of the low-voltage storage battery is A12, acorresponding charging power P4 of the low-voltage storage battery thatmay be obtained is B12; when an SOC value change rate of the low-voltagestorage battery is A13, a corresponding charging power P4 of thelow-voltage storage battery that may be obtained is B13; when an SOCvalue change rate of the low-voltage storage battery is A14, acorresponding charging power P4 of the low-voltage storage battery thatmay be obtained is B14; and when an SOC value change rate of thelow-voltage storage battery is A15, a corresponding charging power P4 ofthe low-voltage storage battery that may be obtained is B15.

Specifically, after the auxiliary motor 5 enters the power generationpower adjustment mode, the SOC value of the low-voltage storage battery,the SOC value of the power battery, and the entire vehicle requirementpower P2 (the sum of the entire vehicle drive power P11 and the electricappliance device power P21) may be obtained, and then whether the SOCvalue of the low-voltage storage battery is greater than the preset lowpower level threshold is determined.

If the SOC value of the low-voltage storage battery is greater than thepreset low power level threshold, the SOC value change rate of the powerbattery is obtained, and the charging power P3 of the power batterycorresponding to the SOC value change rate of the power battery isqueried for, so as to select an appropriate charging power P3 to enablethe SOC value of the power battery to increase; and whether the chargingpower P3 of the power battery is less than the difference between theminimum output power Pmin corresponding to the optimal economical areaof the engine and the entire vehicle requirement power P2 is furtherdetermined. If yes, that is, P3<Pmin−P2, the engine is controlled toperform power generation at the minimum output power Pmin to control thepower generation power of the auxiliary motor, that is, the engine iscontrolled to run at the minimum output power Pmin corresponding to theoptimal economical area, and to charge the power battery at a powerequal to the minimum output power Pmin corresponding to the optimaleconomical area minus the entire vehicle requirement power P2, that is,Pmin−P2; or if not, that is, P3≥Pmin−P2, the output power of the enginein the preset optimal economical area is obtained according to the sumof the charging power P3 of the power battery and the entire vehiclerequirement power P2, and the engine is controlled to perform powergeneration at the obtained output power to control the power generationpower of the auxiliary motor. To be specific, a corresponding outputpower is searched for in the preset optimal economical area of theengine, where the obtained output power may be the sum of the chargingpower P3 of the power battery and the entire vehicle requirement powerP2, that is, (P2+P3 or P11+P21+P3), and the engine is controlled toperform power generation at the obtained output power.

If the SOC value of the low-voltage storage battery is less than orequal to the preset low power level threshold, the SOC value change rateof the power battery is obtained, and the charging power P3 of the powerbattery corresponding to the SOC value change rate of the power batteryis queried for, so as to select an appropriate charging power P3 toenable the SOC value of the power battery to increase; the SOC valuechange rate of the low-voltage storage battery is obtained, and thecharging power P4 of the low-voltage storage battery corresponding tothe SOC value change rate of the low-voltage storage battery is queriedfor, to select an appropriate charging power P4 to enable the SOC valueof the low-voltage storage battery to increase; and whether the sum ofthe charging power P4 of the low-voltage storage battery and thecharging power P3 of the power battery is less than the differencebetween the minimum output power Pmin corresponding to the optimaleconomical area of the engine and the entire vehicle requirement powerP2 is further determined. If yes, that is, P3+P4<Pmin−P2, the engine iscontrolled to perform power generation at the minimum output power Pminto control the power generation power of the auxiliary motor, that is,the engine is controlled to run at the minimum output power Pmincorresponding to the optimal economical area, and to charge the powerbattery and the low-voltage storage battery at a power equal to theminimum output power Pmin corresponding to the optimal economical areaminus the entire vehicle requirement power P2, that is, Pmin−P2; or ifnot, that is, P3+P4≥Pmin−P2, the output power of the engine in thepreset optimal economical area is obtained according to the sum of thecharging power P3 of the power battery, the charging power P4 of thelow-voltage storage battery and the entire vehicle requirement power P2,and the engine is controlled to perform power generation at the obtainedoutput power to control the power generation power of the auxiliarymotor. To be specific, a corresponding output power is searched for inthe preset optimal economical area of the engine, where the obtainedoutput power may be the sum of the charging power P3 of the powerbattery, the charging power P4 of the low-voltage storage battery andthe entire vehicle requirement power P2, that is, (P2+P3+P4 orP11+P21+P3+P4), and the engine is controlled to perform power generationat the obtained output power.

Therefore, at a low speed, the engine can operate in an economical area,and perform only power generation but does not participate in drive, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, improvingcomfortableness, reducing fuel consumption, and reducing noise of theengine, so as to maintain low-speed electric balance and low-speedsmoothness of the entire vehicle and improve performance of the entirevehicle.

As described above, as shown in FIG. 23, a power generation controlmethod for a hybrid power automobile of an embodiment of the presentinvention includes the following steps:

S701: Obtain an SOC value M of a power battery and a speed V of thehybrid power automobile.

S702: Determine whether the speed V of the hybrid power automobile isless than a first preset speed V1.

If yes, step S703 is performed; or if not, step S704 is performed.

S703: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S707 is performed; or if not, step S706 is performed.

S704: Determine whether the SOC value M of the power battery is lessthan or equal to a first preset value M1.

If yes, step S705 is performed; or if not, step S706 is performed.

S705: Control an engine to participate in drive.

S706: Control the engine not to drive an auxiliary motor to performpower generation.

S707: Obtain an accelerator pedal depth D of the hybrid power automobileand an entire vehicle resistance F of the hybrid power automobile.

S708: Determine whether the accelerator pedal depth D is greater than afirst preset depth D1, whether the entire vehicle resistance F of thehybrid power automobile is greater than a first preset resistance F1, orwhether the SOC value M of the power battery is less than a preset limitvalue M2.

If yes, step S705 is performed; or if not, step S709 is performed.

S709: Obtain an entire vehicle requirement power P2 of the hybrid powerautomobile.

S710: Determine whether the entire vehicle requirement power P2 is lessthan or equal to a maximum allowed power generation power Pmax of theauxiliary motor.

If yes, step S711 is performed; or if not, step S705 is performed.

S711: Control the engine to drive the auxiliary motor to perform powergeneration, and the engine not to participate in drive.

S712: Determine whether an SOC value of a low-voltage storage battery isless than or equal to a preset low power level threshold.

If yes, step S717 is performed; or if not, step S713 is performed.

S713: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery.

S714: Determine whether the charging power P3 of the power battery isless than a difference between a minimum output power Pmin correspondingto an optimal economical area of the engine and the entire vehiclerequirement power P2.

If yes, step S715 is performed; or if not, step S716 is performed.

S715: Control the engine to perform power generation at the minimumoutput power Pmin to control a power generation power of the auxiliarymotor.

S716: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery and the entire vehicle requirement power P2, and control theengine to perform power generation at the obtained output power tocontrol a power generation power of the auxiliary motor.

S717: Obtain a charging power P4 of the low-voltage storage batteryaccording to an SOC value change rate of the low-voltage storagebattery.

S718: Obtain a charging power P3 of the power battery according to anSOC value change rate of the power battery.

S719: Determine whether a sum of the charging power P4 of thelow-voltage storage battery and the charging power P3 of the powerbattery is less than a difference between a minimum output power Pmincorresponding to an optimal economical area of the engine and the entirevehicle requirement power P2.

If yes, step S720 is performed; or if not, step S721 is performed.

S720: Control the engine to perform power generation at the minimumoutput power Pmin to control a power generation power of the auxiliarymotor.

S721: Obtain an output power of the engine in the preset optimaleconomical area according to a sum of the charging power P3 of the powerbattery, the charging power P4 of the low-voltage storage battery andthe entire vehicle requirement power P2, and control the engine toperform power generation at the obtained output power to control a powergeneration power of the auxiliary motor.

To sum up, according to the power generation control method for a hybridpower automobile of this embodiment of the present invention, the SOCvalue of the power battery of the hybrid power automobile, the speed ofthe hybrid power automobile, and the SOC value of the low-voltagestorage battery of the hybrid power automobile are obtained, then thepower generation power of the auxiliary motor of the hybrid powerautomobile is controlled according to the SOC value of the powerbattery, the SOC value of the low-voltage storage battery and the speedof the hybrid power automobile, and the power generation power of theengine of the hybrid power automobile is obtained according to the powergeneration power of the auxiliary motor, so as to control the engine torun in the preset optimal economical area, where the auxiliary motorperforms power generation under driving of the engine. Therefore, theengine is enabled not to participate in drive at a low speed, andtherefore the clutch is not used, thereby reducing abrasion or slipfriction of the clutch, reducing an unsmooth feeling, and improvingcomfortableness; and at a low speed, the engine is enabled to operate inan economical area, to perform only power generation but does notperform drive, thereby reducing fuel consumption, reducing noise of theengine, maintaining low-speed electric balance and low-speed smoothnessof the entire vehicle, and improving performance of the entire vehicle.

Finally, an embodiment of the present invention further proposes acomputer readable storage medium, having an instruction stored in thecomputer readable storage medium, and when the instruction is executed,a hybrid power automobile performs a power generation control method ofthe foregoing embodiments.

Although the embodiments of the present invention are shown anddescribed above, it can be understood that the foregoing embodiments areexemplary, and should not be construed as limitations to the presentinvention. A person of ordinary skill in the art can make changes,modifications, replacements, and variations to the foregoing embodimentswithin the scope of the present invention.

What is claimed is:
 1. A power system of a hybrid power automobile,comprising: an engine, wherein the engine outputs power to wheels of thehybrid power automobile through a clutch; a power motor, wherein thepower motor is configured to output a drive force to the wheels of thehybrid power automobile; a power battery, wherein the power battery isconfigured to supply power to the power motor; a DC-DC converter; and anauxiliary motor connected to the engine, wherein the auxiliary motor isconnected to the power motor, the DC-DC converter, and the powerbattery, and when performing power generation under driving of theengine, the auxiliary motor implements at least one of charging thepower battery, supplying power to the power motor, and supplying powerto the DC-DC converter.
 2. The power system of a hybrid power automobileaccording to claim 1, wherein the auxiliary motor comprises a firstcontroller, the power motor comprises a second controller, and theauxiliary motor is connected to the power battery and the DC-DCconverter through the first controller and connected to the power motorthrough the first controller and the second controller.
 3. The powersystem of a hybrid power automobile according to claim 1, wherein theDC-DC converter is further connected to the power battery.
 4. The powersystem of a hybrid power automobile according to claim 2, wherein theDC-DC converter is further connected to the power motor through thesecond controller.
 5. The power system of a hybrid power automobileaccording to claim 1, wherein the DC-DC converter is further connectedto a first electric appliance device and a low-voltage storage batteryof the hybrid power automobile to supply power to the first electricappliance device and the low-voltage storage battery, and thelow-voltage storage battery is further connected to the first electricappliance device.
 6. The power system of a hybrid power automobileaccording to claim 2, wherein the first controller, the secondcontroller, and the power battery are further respectively connected toa second electric appliance device of the hybrid power automobile. 7.The power system of a hybrid power automobile according to claim 1,wherein the auxiliary motor is a BSG motor.
 8. The power system of ahybrid power automobile according to claim 1, wherein the engine and thepower motor jointly drive a same wheel of the hybrid power automobile.9. The power system of a hybrid power automobile according to claim 1,wherein wheels of the hybrid power automobile comprise a first wheel anda second wheel; the engine outputs power to the first wheel of thehybrid power automobile through the clutch; and the power motor isconfigured to output a drive force to the second wheel of the hybridpower automobile.
 10. A hybrid power automobile, comprising the powersystem of a hybrid power automobile according to claim
 1. 11. The powersystem of a hybrid power automobile according to claim 2, wherein theDC-DC converter is further connected to the power battery.
 12. The powersystem of a hybrid power automobile according to claim 11, wherein theDC-DC converter is further connected to the power motor through thesecond controller.
 13. The power system of a hybrid power automobileaccording to claim 12 wherein the DC-DC converter is further connectedto a first electric appliance device and a low-voltage storage batteryof the hybrid power automobile to supply power to the first electricappliance device and the low-voltage storage battery, and thelow-voltage storage battery is further connected to the first electricappliance device.
 14. The power system of a hybrid power automobileaccording to claim 13, wherein the first controller, the secondcontroller, and the power battery are further respectively connected toa second electric appliance device of the hybrid power automobile. 15.The power system of a hybrid power automobile according to claim 14,wherein the auxiliary motor is a BSG motor.
 16. The power system of ahybrid power automobile according to claim 15, wherein the engine andthe power motor jointly drive a same wheel of the hybrid powerautomobile.
 17. The power system of a hybrid power automobile accordingto claim 15, wherein wheels of the hybrid power automobile comprise afirst wheel and a second wheel; the engine outputs power to the firstwheel of the hybrid power automobile through the clutch; and the powermotor is configured to output a drive force to the second wheel of thehybrid power automobile.
 18. The power system of a hybrid powerautomobile according to claim 3, wherein the DC-DC converter is furtherconnected to the power motor through the second controller.
 19. Thepower system of a hybrid power automobile according to claim 18, whereinthe DC-DC converter is further connected to a first electric appliancedevice and a low-voltage storage battery of the hybrid power automobileto supply power to the first electric appliance device and thelow-voltage storage battery, and the low-voltage storage battery isfurther connected to the first electric appliance device.
 20. The powersystem of a hybrid power automobile according to claim 19, wherein thefirst controller, the second controller, and the power battery arefurther respectively connected to a second electric appliance device ofthe hybrid power automobile.